I just had my 10 year old 2HP Jandy Pump replaced with an identical model. My clean filter pressure had consistently been 18Psi and as soon as he fired it up with the new pump it was 24 Psi. I asked him about it and he thought the filters might be dirty but I had just cleaned them a month ago. However, I cleaned them again and the pressure is still 24Psi. He mentioned that the replacement pump, although identical has a 1.1 Service Factor so it operates at 2.2HP (there is a sticker on the motor pointing this out).
Can a 10% increase in HP account for a 6Psi increase in filter pressure ? He found no other issues.