Just updated to latest versions of both Microsoft Remote Desktop and Mac OS 13.0 and application starts, brings up certificate inspection and then usually brings up the remote session like it did yes...
Okay. Solved the problem. The latest version removes the Security permission for Full Disk Access. You will need to turn it back on in order to successfully open the remote PC desktop window on your Mac.
To enable it: Go to System Preferences (if this is the first time on the new Mac OS 13, you will notice the layout has entirely changed). Select Privacy & Security > Full Disc Access. Click the '+' at the bottom of the list to add Microsoft Remote Desktop from the Applications folder.
Now, it should work again.
