A slight addendum to this issue. I was still getting the 24hz problem on a clean reformat and install from my M.2 drive. But going into DayZ video settings, switching to windowed mode, closing the game, reopening in x64 again, then changing resolution to native 7680x1440 works without a hitch.

I did a reformat, and now everything is running smooth at 7680x1440@144hz. It may have been geforce experience, or an nvidia setting. Thanks for the help.

Both the FPS tracker in Steam overlay and the monitor control menu show 24fps/hertz. Using Alt+Tab to show desktop turns the monitors off briefly and reverts back to 144Hz, but entering DayZ again reduces the monitors back to 24Hz. Also, some times Alt+Tab doesn't work, and I have to use Ctrl+Alt+Delete to open task manager, as Ctrl+Shift+Esc doesn't seem to work either. I have tried this in 32-bit and x64 launcher options through steam.

Single monitor running 2560 x 1440 at 144hz is now showing icons.

No error message, just crashes to desktop. Same issue on one monitor. Here is the most recent file: