Hello,

please check if "Don't use optimizations for windows games" is deativated. It should be turned off. Win11 just checked this point for me for FFXIV and it begun to stuttering / no VRR in borderless windows mode.
Please also turn off "Game mode" in Win11. Turn off all options in FFXIV Display Settings below Refresh Rate - select No Limit.

https://support.microsoft.com/en-us/...e-f9389e535952