关闭句首大写更正会导致数学公式自动更正被联动关闭且无法在应用内手动打开。这个问题可稳定复现，并且我已经找到问题所在和解决方法，下面的文档是由 Astra 整理的问题报告。 Disabling “Capitalize first letter of sentences” also disables “Math Autocorrect,” which then cannot be manually re-enabled within the application. This issue is consistently reproducible, and I have identified both the root cause and a solution. The following document is a problem report sorted out by Astra.

PowerPoint for Mac: disabling sentence capitalization also disables Math AutoCorrect, and re-enabling capitalization does not restore it

Summary

In a controlled test on PowerPoint for Mac, unchecking “Capitalize first letter of sentences” also changed the shared Office MathReplaceText setting from 1 to 0. Typing \alpha followed by Space in a newly inserted equation then stopped producing α. Re-enabling sentence capitalization and restarting PowerPoint did not restore Math AutoCorrect: MathReplaceText remained 0.

Directly restoring the relevant configuration allowed Math AutoCorrect to work. The user subsequently confirmed that sentence capitalization can remain disabled while equation AutoCorrect works, with CapitalizeSentence=0, MathReplaceText=1, and MathLaTeXMode=0.

Environment

• PowerPoint for Mac: 16.114.3; CFBundleVersion: 16.114.26102720.
• macOS: 27.0.1; build: 26A434.
• UI language: Simplified Chinese.
• Test period: 2026-10-29 through 2026-10-30, Asia/Shanghai.
• Test presentation: local test.pptx, using native equation regions.
• License type/update channel and input-source identity were not captured. No claim is made about other versions.

Minimal reproduction

Start with the following shared settings and confirm that \alpha followed by Space converts to α inside an equation:

Common/Math Options Settings/MathLaTeXMode = 0
Common/AutoCorrect/MathReplaceText        = 1
Common/AutoCorrect/CapitalizeSentence     = 1

1. Open PowerPoint Settings/Preferences → AutoCorrect.
2. Uncheck “Capitalize first letter of sentences” (Chinese label: 句首字母大写).
3. Insert a new native equation.
4. Type the ASCII characters of \alpha individually, then press Space.
5. Observe that the command remains literal instead of becoming α.
6. Re-enable sentence capitalization, exit PowerPoint normally, restart, and repeat the equation test.
7. Observe that Math AutoCorrect still fails.

Expected: changing sentence capitalization should not disable mathematical symbol substitution. These features should work independently.

Actual: both sentence capitalization and mathematical substitution are disabled by step 2; reversing the capitalization setting does not reverse the mathematical substitution setting.

Controlled test evidence

The following table is reconstructed from contemporaneous tool outputs and agent observations, not a verbatim application log. Values were read from the Office SQLite configuration database by the coordinating agent. UI outcomes were reported by the UI-testing agent.

StageCapitalizeSentenceMathReplaceTextMathLaTeXModeEquation resultWorking baseline110\alpha + Space → αImmediately after disabling sentence capitalization000New equation retains literal \alphaAfter re-enabling capitalization100Mathematical replacement remains disabledAfter normal exit/restart100New equation still retains literal \alphaAfter targeted repair110User confirmed equation behavior restoredFinal requested configuration010User confirmed equations work and sentence capitalization is offFinal values were independently re-read during report preparation. The local archive contains a sanitized JSON snapshot with the capture timestamp. No screenshot files, screen recording, crash report, or verbatim full UI transcript are included in this package. The symptom is a substitution failure, not an application crash or hang.

Separate input-mode finding

Before the controlled capitalization test, the initial configuration also had MathLaTeXMode=1, alongside MathReplaceText=0. Setting only MathReplaceText=1 did not yield a stable repair. Setting MathLaTeXMode=0 as well restored automatic substitution in existing and newly inserted equations, including \alpha, \beta, and \gamma. Those tests passed after two normal exit/restart cycles while capitalization was still enabled.

The initial source of MathLaTeXMode=1 is unknown. Crucially, it remained 0 throughout the controlled capitalization reproduction. We do NOT claim that disabling capitalization sets LaTeX mode to 1. The successful final capitalization-off combination was confirmed by the user and a configuration readback; it was not subjected to a further two-cycle automated restart test.

Configuration location and targeted workaround

~/Library/Group Containers/UBF8T346G9.Office/MicrosoftRegistrationDB.reg

Despite the extension, this file is a SQLite database. Relevant registry-like paths are under:

Software/Microsoft/Office/16.0/Common/AutoCorrect
Software/Microsoft/Office/16.0/Common/Math Options Settings

The following is the minimal SQL used by the final combined workaround. It changes existing entries, and does not create missing entries. Applications were closed and the database was backed up first. This is an observed workaround for this machine, not a claim of an officially supported repair interface.

.bail on
BEGIN IMMEDIATE;
UPDATE HKEY_CURRENT_USER_values
SET value=CASE name
    WHEN 'CapitalizeSentence' THEN 0
    WHEN 'MathReplaceText' THEN 1
END
WHERE name IN ('CapitalizeSentence','MathReplaceText')
AND node_id IN (
    SELECT a.node_id FROM HKEY_CURRENT_USER a
    JOIN HKEY_CURRENT_USER c ON a.parent_id=c.node_id
    JOIN HKEY_CURRENT_USER v ON c.parent_id=v.node_id
    WHERE a.name='AutoCorrect' AND c.name='Common' AND v.name='16.0'
);
COMMIT;

Separate mode correction, used earlier when the mode value was 1:

.bail on
BEGIN IMMEDIATE;
UPDATE HKEY_CURRENT_USER_values SET value=0
WHERE name='MathLaTeXMode' AND value=1
AND node_id IN (
    SELECT a.node_id FROM HKEY_CURRENT_USER a
    JOIN HKEY_CURRENT_USER c ON a.parent_id=c.node_id
    JOIN HKEY_CURRENT_USER v ON c.parent_id=v.node_id
    WHERE a.name='Math Options Settings' AND c.name='Common' AND v.name='16.0'
);
COMMIT;

Backup command pattern used before edits:

DB="$HOME/Library/Group Containers/UBF8T346G9.Office/MicrosoftRegistrationDB.reg"
# BACKUP is a local path selected by the user/script.
/usr/bin/sqlite3 "$DB" ".backup '$BACKUP'"

Full backup databases are deliberately excluded from this report because they can contain unrelated private Office configuration. No sign-in tokens, account identifiers, user document contents, or full local usernames are needed to reproduce the issue.

Other diagnostic observations

• Toggling PowerPoint's regular “Replace text as you type” did not restore the equation behavior during early troubleshooting.
• Word's equation AutoCorrect worked in Unicode mode. Its mathematical replacement checkbox appeared enabled even while the shared value inspected for this PowerPoint issue was 0. Toggling Word's setting did not repair PowerPoint.
• PowerPoint's explicit “LaTeX to Math” action could convert the expression, but this was only a workaround, not a successful automatic-substitution test.
• No clearly exposed UnicodeMath/LaTeX input-mode selector was found in the inspected PowerPoint ribbon/context menu on this installation. This is an observation, not a claim that no such control exists anywhere.
• One intermediate session showed temporary success that did not survive restart. Conclusions above rely on the later controlled tests and explicit configuration readbacks.
• Test presentation changes were discarded. The complete Office container was not deleted, Office was not reinstalled, and the original presentation was not rewritten as a repair.

Requested investigation

Please investigate whether saving PowerPoint's AutoCorrect preferences writes a default or stale MathReplaceText=0 when the user only changes sentence capitalization. Please verify independent persistence of these options, including after restart. Also clarify the intended persistence and UI exposure of MathLaTeXMode on Mac and its relationship to Word's separately visible input-mode controls.

A regression test should start with mathematical replacement enabled, toggle sentence capitalization off and back on, and verify equation symbol replacement in both existing and new equation regions before and after restart. The combination of capitalization disabled and mathematical replacement enabled should remain supported.

Related public documentation

• Microsoft: Use keyboard to create and work with equations
• Microsoft Q&A: Math AutoCorrect does not work in PowerPoint for Mac
• Independent first-person report mentioning capitalization preference changes

These sources provide context only. They do not establish the internal implementation cause of the controlled behavior reported here.