Something does not sound right to me.

Sure, it happens all the time, that aspiring straight razor shavers question the sharpness of the blade, in absence of shaving success, but still, shaving only the sideburn area, in the growth direction of the hairs, should not be a problem, and it should not pull.

It is very easy to dull a shaving edge. Some people try to cut paper, to find out if the razor is sharp. That in itself could easily mess up the edge. Lifting the spine off the strop, or turning the razor over the edge while stropping are two other possible culprits for having problems with the edge.

It's difficult to find out the shaving status of the blade, if you're inexperienced.
May I suggest that you try shaving some arm hair? Put the razor flat on your arm, lift the spine about 2 times its thickness and try shaving a patch of your skin. This should go without any pull, without any effort, and no hairs should survive the blade.
If you can do this, try copying this motion to a well prepped cheek.

Please report back, we'll take it from there.

Welcome to the forums,
don't despair, we're all here to help.

Bart.