Using IMAP login on Outlook mobile app not working

I am having this same issue. I have been using imap email on iOS outlook for years. But since 2 weeks ago I cannot reply email.

I can received all email but cannot reply. I need to start a new email and copy and paste the email I received to reply. Is too troublesome if you know what I mean. Each time I click on reply or reply all on received email, it shows loading and follow by “something went wrong contact support”. 

I contacted MS mobile support and yet to have a solution. It has been working years and it only started 2 weeks ago. I tried in iOS mail and Gmail apps and it is working fine. I prefer to use iOS outlook is because my files are in one drive and I need it while I am traveling.  

I really appreciate if someone can help me with a solution.