Off to the rheumatologist for this one.
You have multi locational synovial inflammatory disease which must have an underpinning rheumatological condition.
Good old fashioned rheumatoid arthritis is the most likely, but you can also consider other systemic conditions such as seronegative disease (was there any psoriasis? ) or gout.
I still think with these locations RA is going to be the answer.
All of these areas you have attached look like synovial proliferative synovitis. I can’t see any erosions or crystal deposition.
The ATFL is an interesting appearance, but I think it is still just a synovial proliferation process of the joint capsule.
Do a rheumatological workup and let me know what you discover.
Steve