during my region band audition on friday my 3rd valve slide just simply got stuck. ill explain everything the whole day my valves were working perfectly fine later in the audition for my second etude between every 5 people they let everyone play a little for 20 secs i was fingering a scale (nothing wrong with 3rd valve slide) then BAM out of nowhere it got stuck. Not like supper glue stuck where i cant even take it out, but it is still unplayable. ive had this sometimes happen before like once or twice and all i had to do what clean the valve then grease it with valve oil. Not this time, and it gets even better, I can't figure out what's causing the problem the valve slide or the valve casing ive put the 3rd valve slide into the 1st and 2nd valve casing and it slides smoothly so that must mean the problem is the 3rd valve casing right? well i put the 1st and 2nd valve slides into the 3rd valve casing and it still slides smoothly i also switched 3rd valve slides with a friend (has the exact same trumpet) and their slide works on my trumpet so i cannot for the life of me understand what's going on. Any ideas other than taking it to a shop?