From August 17, 2021, Microsoft 365 apps no longer support IE11 (the Teams browser client dropped support last year). IE11 fans need to move to a new browser. Microsoft would prefer if you choose the Edge browser, but anything but IE11 should do a better job in the future.
The Outlook Places service uses metadata stored for conference rooms and room lists to help users find suitable meeting places. The metadata surfaces in Outlook’s Room Finder component (shared between OWA and Outlook desktop). Obviously, the better populated the room metadata is, the more useful it will be, once we all start meeting in conference rooms again!
A new Exchange Online feature allows users to send email using any of the SMTP proxy addresses assigned to their mailbox. An Outlook update will make the task easier, but for now it’s reasonably straightforward to insert a proxy address into the From field when composing a new message with OWA or Outlook and send a message.