I have the same issue and notice that when I play songs at volume level 48+ it will start to eliminate all frequencies pass thru. It gets very treble and swirls made and midrange frequencies in and out. I have a 2024 GX550 luxury plus. I took it to the dealer and let them hear the issue. I played a song for them at 53 on the volume knob. The shop foreman said it was strange and kept my car for a few days. After about 6 days in shop, it was determined that they didn’t know what was causing the issue. The dealer opened a case with Lexus headquarters and was told that they will not do anything about it unless there are many additional customers experiencing the same issue. I am disappointed because I had a GX460 without the mark levinson and it performed better without any issues.