Reply doesn't work (intermittently)

Reply doesn't work (intermittently)

Since a while, the reply (and reply to all, edit as new) buttons don't work most of the time.  The 'compose' button still works fine.

The strange thing is, once in a while the buttons work perfectly well for a while.  Closing and restarting the Zoho tab, the browser, or even mij computer doesn't seem to make any difference.

Could you please look into this and solve it?  Thank you!