No disrespect to rdgrimes obvious knowledge, but there is a standard for the tracking of VHS machines, with a tolerance due to manufacturing differences. The makers are supposed to try for the middle ground on this, but it doesn't always happen, hence a tracking control. The odd machine will just scrape through near one of the limits.
No big deal really, unless you happen to have a machine that's on the other limit, then you're screwed. I used to repair VHS recorders and, well most things A/V.
If we had this problem we used to give the customer another machine to try and it always cured it except in the odd case of the original machine being old and badly worn.
Even then we asked the customer for a tape they had recorded and by selecting a couple of machines and some deft careful, not by the book adjustments, we could usually give them a recorder that worked with their old tapes.
This company was a family run business and the customers always came first. It only closed due to the owner retiring.
Not many places like that anymore, more's the pity!