Underexposing OM-2n

One of my Olympus OM-2ns had a recent CLA but still underexposes

Underexposing OM-2n

I have a couple of lovely Olympus OM-2n cameras. One of them was recently serviced, but hadn't been used in a couple of months, so I loaded some HP5 and shot a few mirror selfies to kick off the roll. The meter reading seemed off, so I shot a few frames, unloaded the roll, and finished it the Nikon FE2. I was shooting both of them on Auto and the Olympus is underexposing by around 2 stops. That's disappointing. I don't know if I'll bother fixing it or if I'll just dial up the exposure compensation.