If you have a lot of honewear there is no telling what the previous owners did to that razor to get it sharp.
The angle may be all off now, and the only way to fix it is to either regrind is which is an extreme option; OR more commonly keep honing at a 1K level until your edge starts to hit the hone again.
Of course you can get around all of this by just adjusting the angle yourself with tape so the edge hits the hone better.