This happens often in thunderbird and I do not know how to solve it.
I open thunderbird on one pc and sync inbox with gmail. then I do to laptop and open the same gmail imap in Thunderbird. I read some messages and tag some message as important. When I return to my pc, Thunderbird did not sync gmail inbox. messages still remain undread and untagged. The same happens if I read gmail messages via my mobile phone.
What setting in my desktop thunderbird are wrong so that it does not properly or immediately sync gmail inbox? How can I force syncing of gmail inbox? Pressing
Get Mail -> accountName does not sync imap gmail inbox.