Key fobs keep saying low battery

2016 RAV4 with the smart key. Both of my smart keys keep singing low battery, and sometimes they make the car can't detect them. After I touch the key to the start button, it will work fine for the rest of the day with no warnings.

I've changed the batteries, I've tested the batteries, and there's no issue with the batteries in the fobs themselves.

Had an aftermarket remote start in the vehicle for the past 5 years that I removed thinking that might be the issue, but the issue continued after I removed the box.

I've had it since 2019, and I've never had an issue with it before. My wife has a 2012 Highlander also with the smart key and is not experiencing any problems. So I don't think the age of the vehicle has anything to do with it.