No Oil Pressure on G3X after accomplishing the Purge Perocedure

This started from a mistake during a condition inspection. We  left the drain plug out while doing the compression check. This resulted in pumping some of the remaining oil out while pressurizing the cylinders and spinning the prop. After thinking about that we decided an Oil purge was necessary.  This is on a 912IS engine installed in a 2024 RV12 with the Garmin G3X touch system. We accomplished the Purge procedure steps according to the steps in the manual, as applying 10psi to the tank, capping the return to the tank, taking out bottom spark plugs, etc. However we never get any oil pressure to display after several hundred rotations of the prop. We do have oil coming out the return line.