Copilot in Teams - loads then goes blank

I just forked out for Copilot for business today... not a great start.

Had a play with an agent, seemed to work ok. 

But now if I open the Teams Copilot it initially loads the example prompts, the right sidebar remains blank, then the whole screen goes blank.

I've reloaded app, deleted temp files in appdata, repaired and reset copilot. Any suggestions of what next?If it's the agent i created, where do they even live to edit them - only accessible from within Teams?

Any help much appreciated