Sounds like an older crankset that has been removed and re-installed a few (or many) times. Each time, the taper flats of the crank get pushed out a touch farther so the crank has to slide on more to tighten properly.
Or: manufacturing tolerances. Tiny differences in the taper size of the spindle will make noticeable differences in where the crank sits. (I've seen differences in Phil Wood spindles. Probably nobody's exactly perfect here.) Or perhaps both of these are happening. (As I recall, the flats are a 9 degree taper. At that taper, the crank position will change 6 times as much as the variation from spec taper thickness.)
Other possibilities: Any chance you've got the spindle swapped right side for left side? With most that's not possible but it can be done with some. Also there are two different tapers. Shimano uses one (as does Sugino and SR for most of their cranksets). Campagnolo and the high end Suginos use another. The two standards are the same taper so both can work with no harm to the crankset but where they sit relative to the frame is quite different. The Shimano standard is called JIS and the Campagnolo ISO.
For more info see the Sheldon Brown website.
I've always found that until I actually mount a crank, I don't know exactly where it is going to sit. (And I love Phil Wood BBs for the adjustability mentioned above. That and they will make any length and asymmetry for the listed price. You just might have to wait a bit.
Edit: is that crankset still on the bike? Get a headlamp and stick your head behind the seattube and under the frame and see if the crankset is hitting the BB or frame BB shell (or chainring teeth and the chainstay). That the crank won't turn is only a mystery until you find the contact,
Last edited by 79pmooney; 07-28-21 at 10:02 PM.