Blowing trans filter o ring. Deere 310

Machine is actually a 210le with a powershift transmission but it is the same as a 310. Not long ago I had to have my intermediate plate replaced on the back of the transmission because it developed a hole from corrosion caused by chicken manure. Today I was grading with the tractor and it blew the O-ring off the transmission filter. I pulled the filter fix the O-ring and it blew again within 10 minutes. Obviously there's too much pressure building somewhere. What should I look for.

Blowing trans filter o ring. Deere 310