My in-camera meters, Nikon N75, Nikon F100, Hasselblad 503 CX with the 45 PME, are all spot on and agree with my Gossen Luna-Lux Pro incident and reflected, all the time. What would you classify using my Nikon F100 as a spot meter for my Hasselblads, 4"x5" Pacemaker Speed Graphic, and 4"x5" Graflex Model D, is that hand held or in camera, which it technically is, for large SBR?

I really suspect that your problem is rather a calibration problem or an Operated Assisted Failure mode, of which the later makes an interesting acronym.