There is only one condition where this can be true and that is with a 2 speed pump. Going from low to high speed, you are effectively changing the HP of the pump so you will see both a rise in PSI as well as suction.

Assuming the same pump and speed, and the PSI rise is due to a dirty filter, solar or other return restriction, higher filter pressure = more head loss which means less GPM. Less GPM = less suction. This what hydraulic theory dictates and what I have confirmed through measurements.

If you had a suction guage on your pump, you would see it drop with higher filter PSI. However, just the opposite happens when the PSI drops so perhaps this is what you are experiencing.