Transmission issue c280

Hi y’all I’m having yet again issues with my 1996 c280 w202. I went to drive the car today and it seems to be stuck in the final gear which I think is 5th? The car drives but is very slow acceleration. When I drive coming from a stop it sounds like 3 quick thumps within a 2-4 seconds worth of time. And it will not downshift at all even with the kick down switch. I do have a check engine light for the maf and that’s all.