Can you whistle? Are you much of a whistler? Ive done that occasionally and have found I’m above average at it. I know it’s not a direct correlation to playing trumpet, but it could provide an indication.
Do you think you might be flexing/engaging the lip tissue as you ascend? Or are you sure that you are keeping the red part of your lips relaxed and only engaging the corners?
It’s possible that you have a physical impediment, but probably less likely than the usual causes we all have faced.
I’m not a qualified instructor, that’s just my opinion, FWIW.