whiteboard in breakout rooms after meeting is over

[David Phillips]

One of my users recently discovered that meeting attendees are unable to see whiteboards generated in breakout rooms after the meeting is over if there was no chat in the breakout room.  The whiteboard is visible at whiteboard.microsoft.com, but if no one chats in the room, there's no "anchor" for meeting attendees to go back and view the whiteboard unless they actually rejoin the meeting.  Is this by design?

[#2]

If the whiteboard is visible via whiteboard.microsoft.com then it is by design: those persons participating in the Whiteboard during the meeting can access it via their Whiteboard app (either web or Windows/Mac app). That is how Whiteboard works.

Even if there was chat during the Breakout Room people can not rejoin the room if rooms are closed.

If you want to make those Whiteboards more visible then I suggest that someone in the BO Room meeting copies the Whiteboard link to the chat and thus it appears in the chat to all room participants and also allows accessing the Whiteboard quite easily afterwards. This is a kind of best practice when you use Whiteboards in Teams meetings.
I use Whiteboard App on Windows most often but sometimes access my boards via web app (whiteboard.microsoft.com) - it is good those boards appear there automatically and I have come to rely on them quite a lot. But since it is IT I still try to remember to copy off the URL to Whiteboard in the meeting. :)