Can't remove messages from folders

I use IMAP to link my Gmail account. When I try and delete a message from a folder (or label) in em client, it tags it as deleted and appears in the deleted folder, but doesn’t go from the original folder. Any ideas how to resolve this would be much appreciated as it worked fine a few days ago. Works fine working from the Gmail web app.

Just to say that I fixed this issue. 
In gmail settings, I never had ‘show in IMAP’ ticked for the Bin.
Simple as that. Took me several hours to work this one out. Grr!