Our 2018 Touring L has done the same thing since new, not to mention issues with compromised primary and auxiliary batteries, sliding doors that periodically won't open and close using the motors and a driver's door rattle that can make you crazy. The dealership tried reprogramming the Uconnect system and then replaced the entire center stack but it still exhibits this behavior 90% of the time.
My daughter bought the same year/model about the same time, unfortunately based on my recommendation. While she has not had this radio problem at all, she has had the same battery issue, a sensor problem that caused the check engine light to come on and one incident where the parking brake turned on by itself and wouldn't disengage or allow the ignition to be turned off. Her van had to be dragged into a flatbed and be towed, while still running, to the dealership so they could override the ignition and turn it off. Then, they could not duplicate or diagnose the issue.
Between the two of us, we have had our vehicles back to the dealership eight times within the first two months of ownership and some problems still aren't fixed.
Guess what I am saying is that these vans are full of software gremlins that are causing all sorts of problems that then cannot be duplicated. I would strongly advise anyone considering a minivan to look elsewhere unless they like rolling the dice.