Inbox unresponsive during the last weeks

[heisenberg2980]

My inbox has been very unresponsive during the last weeks. For example, I move an email to a folder and it reappears in the inbox again, I mark an email as read and it marks itself as unread, and similar issues. The strange thing is that none of these issues seem to be reflected in the status of the monitors, as all appear as operational 100% every time I look (even during the times I am having these issues).