Very difficult question to answer without seeing how you press in person. It could be one of a magnitude of reasons:
Muscle imbalance
Technical difference left to right
Scapular position
Dumbbell angle
Neural issues
Previous injury/scar tissue
Does it also happen on bilateral movements like a bench press or incline bench press?
I can definitely tell as well on most presses. The range of motion from side to side is different so I think it’s more a imbalance with the scapular.. thank you for this