Plastic cover for a milk microwave under which meat is heated in the microwave. What is it?

This is a multi-purpose microwave (it heats all types of food)
There was a soup bowl with meat in it with a ”protector” on it is a plastic lid that we use for dairy foods that are heated in the microwave
The question is about the lid
And actually also about the bowl (which I don't know what it is now because it was mixed with other bowls)
Thank you very much

I think that if it came to a boil, the bowl and lid are prohibited. I'm not addressing the question of ingestion by plastic (in light of Pixler's research findings). I don't know what they came up with regarding plastic.

Yours sincerely
A. I don't know if heating for 2 minutes in the microwave is considered boiling.
B. The bowl in which the food was cooked got mixed with the other bowls and I don't know what it is. What is the ruling on the bowls?
C. Does the fact that plastic is not new have any significance? Is the repair of the dishes in the scald, or will plastic not benefit from the scald?

A. I think so. It comes near a suleda.
C. If it was not a new-born, there are opinions that the vessel is permitted. In particular, if it was chicken and not meat, it is easier. There is no objection to plastic.
B. If there is a great loss in having to throw away all the bowls, it can be added that the vessel was not a new-born and permitted by the ruling of invalidation by majority (even though it is a significant vessel that is not invalid by majority).
As in

Thanks
Regarding section b, “If it was not a newborn, there are opinions that the vessel is permissible”: Do you also mean the plastic cover under which something dairy was not heated for 24 hours, or do you only mean the bowl in which there was meat (not chicken)?

What's the difference? The lid is lighter than the vessel itself because it doesn't touch the meat.