Mail app on MacBook Pro not syncing, but Outlook/iOS devices sync correctly

I have a MacBook Pro (Tahoe), iPhone, and iPad, all of them updated to latest version. On all my devices, I use both my Apple account and an Exchange account.

A few weeks ago, even before updating, the Exchange account in the Mail app on my MacBook Pro stopped reflecting any actions I take on other devices or in Outlook.

Everything I do in Outlook, iPhone, and iPad syncs correctly across all devices. However, anything I do in the Mail app on my MacBook Pro does not sync to the other devices.

I can still receive emails normally in the Mail app on my MacBook Pro.

Here’s what I’ve already tried:

• Removed and re-added the Exchange account in Mail → no change.
• Logged in as a different user on the MacBook Pro → no change.
• Deleted and rebuilt the Envelope Index files → no change.
• Checked with my company’s IT team → nothing was changed on the mail server, and everything looks normal from their side.

This issue only happens on my MacBook Pro. On all other devices, everything works perfectly.

Any recommendations?