Missing emails

Winddows10 Office 365.
For some unknown reason any emails I receive after 02/20 disappear. I receive several emails during 03/04/20 but for some unknown reason they have all disappeared. They are not in my Delete or Junk box. Has anyone any idea what the fault can be please? I also use Outlook and I don't have this problem there? Any incoming email on Hotmail which are kept disappear before 02/20 ones??
Please see the attached and if you can help I would be very grateful.

This may or may not be related to your problem, but it has caused some problems with my email setup. If you or someone sends an email to you and to 1 or more lists that you are on, you will likely only get the copy that was sent directly to you -- leaving off any list-specific information or stamping.

Google discards anything they consider to be a copy (even though the mail through a list reflector and to you directly aren't the same due to list headers and email path) -- google only pays attention to the first copy of the content it sees. Anything else isn't stored or processed.

So if any of the emails you are missing may have their content in your Sent file or some such place, there's a good chance that google has disposed of the other copy for you. They call this mandatory deletion a "feature" and seem to think everyone loves it so they don't bother to make it an option. Of course the realize is that anyone using gmail is allowing google to index their email as part of their AI-training and google doesn't want to really store all the email you get -- only the unique copies that you get. They can store pointers (via labels) so it will sort in multiple places, but they really only want 1 copy.

Perhaps some variation on this has bit you.
Cheers and good luck finding your emails. At the very least, you might try signing into gmail and looking through the normally hidden "All mail", which contains all your emails that you have not explicitly purged.