FM radio looses signal
 

The FM radio in my 2018 Pacifica with 19km periodically looses all but 1 or 2 FM stations and I live in an area with many strong stations.
It happens after I've been driving for over 45 minutes to an hour and is not repeatable However, pressing the AM band and then
return to the FM band and all the FM stations re-appear. Have not taken the car back to the dealer yet. Any suggestions?