TB 52.9.1 not updating unread email folders

[hmp3]

Hi, I've recently changed my email accounts from outlook to gmail,
Have setup gmail rules to file to specific emails to specific folders.
But despite not changing my TB setup, I notice many of my folders not becoming bold to show new emails until I manually click on the folder.

But I've noticed that some of the new emails were sent to me 24hours earlier, but still not alert despite the fact that I restart TB many times during 24hours.
Just incase, I tried changing TB to check every 5minutes instead of 10minutes. But TB is still not bolding these folders.
Why is this happening and how do I resolve TB to alert me of unread folders without me having to manually click on them?

[DanRaisch]

How is the account set up in Thunderbird, as POP or IMAP? Find out using menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue.

[hmp3]

IMAP

[hmp3]

I logged into gmail manually which showed 4 in bold next to a folder to indicate it's unread.
In TB I manually clicked "Get New Messages" for that email account and still, TB did not update that folder to show it has 4 unread messages.