Recent upgrade to Microsoft365 and by extension Outlook365 (and the cloud) no longer grouping emails by conversations. All of the recommended settings to maintain emails by conversation have not been changed and they are all set instructed, but Outlook fails to group by conversation - which is especially necessary as emails are moved to folders other than the Inbox.
One recommendation I saw advised to Group by Date... this isn't a solution since conversation threads can span days - weeks even.
Another workaround I read as a recommendation was to Group by Flag... that would mean every single email in the conversation thread would need to be flagged and assigned a separate flag for each conversation. This is wholly unacceptable and more cumbersome than doing nothing.
The problem this failure to Group by Conversation presents is time spent searching for portions of a conversational thread that are in different folders (heaven help us if it is misfiled). The other part of this that has been lost was the notation visible on each email in the thread that identified which folder it was filed in.
The failure of Microsoft365 to retain this functionality is making managing email communication next to impossible - especially given the virtual office setting when more than 90% of corporate communication is transacted through emails.
PS... I was required to TAG this post. I have no idea which TAG applies so I just picked one. It's a Microsoft 365 / Outlook 365 issue, I think... there was NO TAG for EITHER