.ics invite emails not showing in inbox
I have a new Thunderbird installation - IMAP account. I cannot see invite emails (containing .ics) in my inbox. I can see them on another Thunderbird installation, I can see them on outlook, I can see them when I go to full search, but they don't show in the inbox.
When received, I hear the audio alert - but the number of new emails messages does not increase, nor does it display.
(It's not in junk, I haven't deleted it - the main search shows it's in the inbox folder, but it's not visible on the inbox tab).