I have two of these in a dual monitor setup and have the same exact problem. The main monitor will maintain 240hz but the second one will switch to 120hz when you reboot the computer. If you toggle the vrr it will turn back on.
4090fe, 13900k, MSI z6...
My z690i is getting WHEA-Logger 17 warnings. The system is stable and I haven't had any issues. Just the event viewer shows these warning frequently. Is there a reason to be concerned if the system is stable?