I would venture to guess, actually I’m quite certain, any of you experiencing large pressure fluctuations in their tires have very moist air in those tires. I would suggest getting them filled with nitrogen. You will of course read that nitrogen changes pressure with temperature, yada yada. The reason nitrogen primarily is more stable is it is free from moisture which expands and contracts at MUCH greater rates than air’s other components. This is why aircraft use nitrogen as they can leave the ground at 100 degrees, cruise for hours in temps below -40, then land still having sufficient pressure.
This is always a big to do, people are very opinionated on this subject. I will say this; I have a fleet of on road emergency vehicles with nitrogen in the tires. I own an aircraft with nitrogen in its tires. I have a Grenadier and a couple other personal vehicles with nitrogen in their tires. I do this because it works better in my experience. Period.
Nitrogen can be had at many, but not all tire shops. I believe Costco still has it available. It can also be acquired from welding/compressed gas vendors which are everywhere.