Thunderbird not showing new folders in the left bar

I have a sieve script creating new folders on the server side as needed, and automatically subscribing clients to them.
The issue is for some reason thunderbird doesn’t display it in the left bar until I fold and un-fold the parent.

Is there a trick or an addon to get thunderbird to refresh the left bar automatically when getting a new email ? I’m using thunderbird 83, and I tried ticking / unticking everything I found including the mail.check_all_imap_folders_for_new option in the config editor without any success.
The folder does get subscribed, the left bar just doesn’t refresh automatically.