The ability to move a mail to a folder seems to have stopped working.

I used to be able to either drag the mail to a folder with the mouse, or select it with a tick box and then pick Move To from the menu bar. 

However, in the last few days, this has stopped working and now, no matter how many times I do it, the mail remains stubbornly in my Inbox.

This seems to be the same whether I use the webmail interface or the Zoho mail iOS app.

Great if you can advise how to get this fixed.  Thanks.