Mail stuck downloading messages - Tried Everything

Mac mail is stuck downloading messages on my IMAP account. Cannot be used for anything.

I tried everything I could find online.

• Deletes and reconfigured the account,
• Deleted the Library files
• Reinstalled MacOS and updated everything
• Installed a different email client, which worked perfectly

So, I'm now looking for any advice on this.

My device is a Mac Studio M1 Ultra and I'm running Tahoe 26.0.1