can HD46505R CRTC work in a PET?

Hi all,
I am servicing a few PETs, all are "universal board" types.
In one of them I've found an HD46505R CRTC, it was socketed on a previous
repair attempt, so I don't know all the history of this machine.
However, it didn't produce any sync until I swapped the CRTC for a R6545
one.
I've quickly had a look at the Hitachi datasheet and it seems that the
difference lies
on the Status Register, present on the 6545 but missing from the MC6845
compatible CRTCs like the Hitachi. Is that a good reason for the PET
failing to initialize the display controller?
Thanks in advance.
Frank IZ8DWF