Missing Emails

[Silvi1380]

Hi, I sent an email this evening, and all of a sudden all my emails from my inbox (about 30) disappeared. I've tried to search for a couple that I knew the sender, have looked in my deleted folder & spam, but nothing. I cleared my filters & all of a sudden all my emails I've received since creating the account appeared then disappeared again. Any ideas?

[#2]

I'm actually in the very same situation. The problem is impacting many users from my company. This may or may not be connected, but another problem popped up at the same time : Folders and e-mails started to duplicate somehow.

We're using Office 365 (build 2104) on Windows 10 (2004 or 20H2).

Edit : The second problem is happening when you have subfolders in your inbox and rules sorting automaticaly e-mails to them. To fix that, your subfolders must be anywhere but in your inbox. This problem occurs more often with read e-mails.