Disappearing coolant

[Hpsportsfanatic]

I am dumbfounded. The reservoir falls below the min line so I fill it to full. A day or 2 later and it’s back to the low line. It’s a 2014 Impreza hatchback sport with 75k on it.

no visual leaks or puddles
No visual puddle in the engine chamber
Pressure tested radiator... passed
Pressure tested radiator cap... passed
No Smokey tail pipe exhaust
No milky oil
No overheating alert
No sweet smell