我也遇到相似的问题，使用agent分析：

Edge sync stuck at "Setting up sync" after every restart (personal MSA)

Environment

• Windows 10 Pro 23H2, build 22631.6199
• Microsoft Edge Stable 156.0.4314.50 (64-bit); the same behavior was reproduced on 156.0.4314.42 on the same machine
• Personal Microsoft account (MSA)
• No sync-related policies configured; other Microsoft endpoints work; TCP/TLS to edge.microsoft.com succeeds

Symptom

After every full exit and restart of Edge, sync remains at "Setting up sync" indefinitely.

edge://sync-internals in that state:

• Transport State: Initializing
• Auth Error: OK; main sync token and KeyData token both OK
• MSA Account Key Status: Download Key Result: Fail (HTTP/Net: n/a)
• Sync Engine: BlockReason: NotStarted; Syncer: Unset
• DataType Manager: Stopped
• Server Connection: not attempted
• Sync Protocol Log / Type Info: empty

Signing out and back in restores sync for the current session only; the next cold start breaks again.

Evidence

Working (after sign-in):

NudgeForInitialDownload Encryption Keys
Control Types added: Encryption Keys
ConfigureSyncer ... reason: 3
...
Started DataTypeManager configuration
Configured DataTypeManager: Ok
DoStartSyncing -> Start syncing

Failing (cold start):

DoInitialize -> Control Types added: (empty)
ConfigureSyncer -> Types to download: (empty) with reason: 4
DoUpdateKeyDataCredentials / DoUpdateCredentials
(no StartConfiguration, no server request, no commit)

Fresh local sync state (local Sync Data folder reset only; server data untouched):

DownloadKeys: Success, Key count: 10
SetEncryptionKeys: Success
Initial GetUpdates: NEW_CLIENT -> Success

The next restart again logs empty control types and stalls.

A/B observations

• Same machine, same Edge build, a newly created MSA (1 key): syncs normally across restarts.
• The affected account has 10 historical keys (accumulated over several years).
• A fresh Edge profile or a clean Windows VM with the affected account: first sync works, next restart stalls.
• Resetting sync / clearing cloud data did not fix it (and local content was not re-uploaded).
• Reinstall/repair, deleting the profile or local Sync Data: works for one session only.
• Forcing a key refresh by editing the cached keystore state: no effect.

Suspected cause

On cold start, the sync engine initializes with an empty control-type set when cached keys are already present, then calls ConfigureSyncer with an empty type list but never calls StartConfiguration. The DataTypeManager stays stopped, no sync cycle starts, and no server request or commit occurs. The sign-in path and the fresh-local-state path (which force a key download) avoid the problem.