It sounds like there is something with your technique that is not ideal. First of all, try to identify if you do something different on each side, since it's only the one side that's a problem. Then try to play "symetrical""symmetrical" so the tension is equal on both sidesides.
If you don't discover any difference, you should contact a trumpet teacher thatwho can help you with your technique.
If the teacher can't help you, you might want to seek help with a physician.
