So I use the 365 office login, then pick outlook. For me, I cannot get it to search correctly. I pick a subfolder in my inbox, set a date range, and no emails show up, knowing there are emails in there. Does it not search subfolders?
I don't even see an option to select a subfolder, I can only select "first level" ones. I'd suggest using the "all" option and narrowing down the search by other criteria.
@Vasil MichevNeither works. If I select all, pick a date range, I get 0 emails. It should not do that.
If you can reliably reproduce this, open a support case.