Deleted Gmail emails remain in Inbox on iOS Mail app

Hello,

I’m experiencing an issue with the iOS 26 Mail app using a Gmail account.

When I delete an email from the iOS Mail app, it is correctly moved to the Gmail Trash on the server. Other clients (Mail on macOS, Gmail in a web browser) reflect this properly, and the email is only visible in the Trash.

However, when I delete an email from Mail on macOS or from Gmail in a web browser, in the iOS Mail app the email is correctly shown in the Trash but it also remains visible in the Inbox. The only way to remove it from the Inbox is to delete it again directly from the iOS Mail app.

I tried removing and re-adding the Gmail account on iOS: during the initial sync, deleted emails were not shown in the Inbox (as expected), but after that the same behavior started occurring again with subsequent deletions.

What could be causing this strange behavior?

Thank you.