Delta Temp2O shower slow drip all day

[Mccun935]

Have a 5 year old new construction home with a Delta Temp2O valve that drips throughout the day. As an example, the shower was last used last night at 8PM and 12+ hours later the spot under the head in the pan is still wet. Roughly a drip every 30-60 minutes, just enough to leave the shower pan tile wet constantly. You can see in the photo the wet area.

I replaced the main valve cartridge back in November with the EP78407 Temp2O 14S Cartridge as sent by Delta. Unfortunately, still dripping.

Could this be a PSI/pressure issue? Any tips or help, much appreciated!