First thing I would do is check the pressure
with a manual gage like this one.
Check it at the back of the engine behind the distributor.
That will let you determine if your gage is
telling you the correct info.
I have run an oil filter like that before.
The orifices will affect the pressure.
After you check the oil pressure I would clean the filter.
That would be my approach.
You could clean the filter first.
.