2011 Chevy Malibu loses tire pressure on all four tires.

What is your question?

I bought a 2011 Chevy Malibu in 2014. Around 2019 all four tires started losing pressure. So I bought 4 new tires and it still lost pressure. I took it back to the garage and they put on 4 new valve stems. It is still doing it but more frequently now. Each week. Tires are all inflated to 30 psi. A week later I see it says: FL 29 FR 25 RL 27 RR 28 I'm at a loss. I fill them up before I go anywhere to 30 psi. within 3 days the front right tire is the worst. It has dropped down to 22 psi within a week to 10 days.

How long has your 2011 Chevrolet Malibu had this problem?

Over a year