IMAP client and web interface do not stay in sync

IMAP client and web interface do not stay in sync

Hi. I am accessing my Zoho account in two ways - via the web interface and via Thunderbird using IMAP.

I can read my mail OK in both places. But any changes I make in one interface are not properly reflected in the other.

For example, if I delete a mail in Thunderbird, I can look on Zoho and it is still there. There are various ways to delete in Thunderbird. You can mark it as deleted or move to trash. Whichever option you use, it is still not deleted in the web interface. The same thing seems to happen in the other direction too.

I tried signing out of Zoho but that didn't help. Also closing Thunderbird didn't help. The two interfaces still display inconsistent lists of messages.

I read somewhere that it might settle down after 24 hours, but that seems too long to wait. Can you help, please?