I had a similar problem with my BX2200. I can't remember exactly what the symptoms were, but fuel starvation came to mind at the time.
I bought both fuel filters, and changed the one near the fuel pump. Cut it open and it was terribly dirty! Of course, first change in about 18 years. (red face here). That was a couple years ago. Still have not got around to changing the easy one next to the engine.
Add my vote to changing the filter near the fuel pump, which is the first filter in line and likely to be the culprit.
GoeHorn's suggestion is also important to try. Many threads here on BX tractors where blocked fuel tank venting caused an issue like you are having.
edit: Another somewhat common issue is something floating around at the bottom of the fuel tank, which blocks the fuel exit point intermittently and causes symptoms like you are describing...