IMAP issues: 1) Operations do not succeed - 2) Emails get placed twice in Sent folder

IMAP issues: 1) Operations do not succeed - 2) Emails get placed twice in Sent folder

I use the latest version of Thunderbird on Windows.

Two isues pop up (only) with my Zoho Mail account.

The first issue is an error message along the lines of:

"The current operation on "Drafts" did not succeed. The mail server for account xxx@xxx.com responded: [CANNOT] Invalid target folder"

I get the message when trying to delete an email from the Drafts folder or when trying to move one from the Trash folder back to another folder.

The second issue that sent emails are sometimes placed twice in the Sent folder.

Any ideas on what to do here?

Thanks