939C bucket valve sticking

Hi all, got a CAT 939 here. When you raise the bucket, if you pull far enough on the joystick (not much), it locks in like the float mechanism does. It will do it when curling the bucket too. I'm not sure what the pilot pressure is as I don't have a gauge to read it but I'm really starting to pull my hair out. It never used to do it but recently its just started doing it. Any help would be appreciated. Cheers