I have the same problem with my 2022 QX50. After attempts to reset it failed twice, the dealer replaced my audio visual unit (the screen also would randomly reboot as well). The clock was fine for a while but then suddenly was off four hours and then this week, it's off by five hours. I can't manually reset it. A friend thinks it may have to do with some kind of software update but I also am having trouble manually updating software.
I too am very disappointed and disappointed. At this point, I am thinking of selling it after only 19,000 miles.