Process of elimination.
First make sure you are shaving with a good lather & the razor nearly flat on your face.
Then shave minus the leather strop then the nylon then the paste etc, right down to 1k. Once you get down to a 1k shave you will see which stage your problem is.
90% of the time the problem is at bevel set.

And/or buy some magnification & learn to see what edges look like. Depends on if you are a visual or kinesthetic learner.