MrMaestrolIRL… The last few days was struggling with the Gaming Services pop-up issue too, which after much fiddling devolved into this 0x80070002 error code screen:
Then I ran across the steps in this post and followed them to the letter:
After following those steps, Gaming Services again popped up when trying to boot the sim, but then after hitting the “Repair” button at Settings>Apps & Features>Gaming Services>Advanced options then it worked… and MSFS began booting as normal. I’ve booted up now a half dozen times with no error. Your success at trying this may vary of course, but it worked for me.
Edit: To be sure, I’d hit the “Repair” button before many times (as that alone had worked for others in this thread) but to no avail. Not until I followed the PowerShell commands outlined in the linked post above did it finally work for me. Apparently the PowerShell routine disables then reinstalls a new copy of Gaming Services, which for some reason fixed my issue.