What you describe sounds like a VERY common problem with many Toyota models. We had a 2014 4Runner that did EXACTLY what you describe. It got worse over time, and the radio froze 11 times during one lengthy road trip. The good news is that a trip to the dealer to get the radio's memory chip(s) refreshed fixed the problem and it never occurred again. I hope your sequoia is still under warranty or it will cost you.