Mobile app Sub folder notifications

There has been a BUG with Outlook For Android Search and IMAP email accounts for many years that is probably associated with this.
(If you use an Outlook or Gmail email address all seems Ok.)

But if you use a different IMAP email provider, and use Folders to save read emails in, the Outlook Search function will never find those emails in the folders.
It will find emails within the Inbox, but the moment you move them to another folder nothing will ever be found.

I have reported this to Microsoft many times, and have had confirmation from them there is a BUG and they are aware of it...
But the BUG never gets fixed, and the next time I report the BUG they start all over again saying they have never heard of such a BUG and it must be my phone, etc., etc...

But a quick Google finds many users have issues with the exact same BUG - I guess Microsoft Support don't know how to use Google???

Just in case this BUG is associated - I am once again stuck in a Support Loop with Microsoft Mobile Outlook trying to get this fixed, but getting nowhere...