Since everything is already updated and reset was already tried, focus on the message sync prerequisites and the Android-side settings that commonly block Phone Link message sync:
- Verify the same Microsoft account is signed in on both devices.
- In Phone Link on the PC and Link to Windows on the Pixel 8a, confirm the same account is being used.
- Check Android permissions for Link to Windows.
- On the phone, open Settings > Apps > Link to Windows > Permissions.
- Make sure SMS-related access is allowed.
- Also confirm notifications are enabled under Settings > Apps > Link to Windows.
- Turn off battery restrictions for Link to Windows.
- On Android, go to Settings > Apps & notifications > App info > Link to Windows > Advanced > Battery > Manage Battery Usage > Battery optimization.
- Find Link to Windows and set it to Don't optimize.
- On some Android devices: Settings > Apps > Link to Windows > Battery > Optimize battery usage > All > Link to Windows > Off.
- Battery optimization can interrupt the connection even when the app shows as connected.
- Make sure Do not disturb is off on the phone.
- Go to Settings > Sounds or Sounds & Vibration / Sounds & Notifications and confirm Do not disturb is Off.
- Check that Phone Link can run in the background on the PC.
- On Windows, open Start > Settings > Privacy > Background apps.
- Ensure Phone Link is enabled.
- Check Windows shared experiences.
- Go to Start > Settings > System > Shared experiences.
- If Fix now appears under Accounts, select it and complete the prompts.
- Fully unlink and relink the phone instead of only resetting.
- On the phone: open Link to Windows > tap the Microsoft account under Linked Account > Account Settings > Sign out and unlink account > confirm Unlink.
- On the PC: open Phone Link > Settings > Devices > Add new device and pair the Pixel 8a again.
- If reconnecting still fails, restart Phone Link on the PC after relinking.
- If the issue started after an Android update, recheck permissions specifically for messages and notifications.
- On Android: Settings > App Info > See all apps > Link to Windows > Permissions.
- Allow Storage, Contacts, SMS, Phone.
- For notifications: search Notification access, turn Link to Windows off and back on, then select Allow.
If messages still do not sync after those steps, send feedback from Phone Link > Settings > Feedback & Community > Send feedback so diagnostic data can be attached for investigation.