Does the 90-day reporting period reset after changing from a work visa to a marriage visa in Thailand?

nope it does not

BUT

Here's an easy way to tell if your 90 day reporting date was reset when you applied for a new extension

IF they gave you a new 90 day report receipt with a new reporting date, when you got your yearly extension they DID reset your 90 day reporting

BUT

IF they didn't give you a new 90 day report receipt when you got your yearly extension they DID NOT reset your 90 day reporting and you need to go when the receipt you have says to