Hi mrsaberhagen - I am in the same situation as you, also since last March, so understand how completely frustrating this past year has been. I had the medical 3 days before lockdown began.
And after checking almost daily for the past year, I was very relieved to find available appointments - although there were only 3 remaining towards the end of June, I didn't hesitate to to grab one.
I also have the the CEAC notification that the registration was cancelled - which does still worry me slightly as I've not had confirmation that this just an automated response - it would be great to get clarification on this.
Can I ask, were you advised to get a new Medical, or are you just doing it again to be 100% sure? I tried to get clairty on this from the embassy but they just pointed me at the FAQ which isn't clear. The FAQ only mentions possible extending medicals for RE-issuing K-1 visas.