i have found that this only happens on window mode, if i leave the FFXIV window and start using another window lets say google chrome, the UI timer will offset and somtimes when going back to ffxiv window ill get red connection icon and UI is non responsive for like 5 secs the i get green connection ui responds but timers are off.

if you can please confirm this i think it would help devs to know whats causing the issue.

to test try playing full screen for like an houra and see how often if it happens, your timers show the wrong timer. then set windowed mode play, then chose another windows window then back to ffxiv and check timers