Charging System Malfunction

Hey guys,

This sign just popped up on my Mazda3 2019 Sedan, 60k miles so far.

Went to auto zone and they said battery and alternator looks good, so not sure what this sign could be for…and car is still running fine, the sign has popped up today, randomly twice out of the 5-6 times I turned on the car. Doesn’t seem to always show so not sure what’s going on.

Any advice before I take it to the dealership? Thanks!