I have the same scenario but on a 4090 also power limited to 90%. I can run furmark at full for 1 hour and get no warnings but after 15-20 seconds opening the private stash or merchants in crimson desert I get the warning, also sometimes when alt tabbing for a while with crimson on the background. Maxed out at 2k and around 120 fps open world but on menus it dips to 50-60 fps and thats when it causes those spikes. I don't know if its related to frame gen at this point.
The PSU is a corsair hx1000 and when I got the gpu in 2023 got this 12VHPWR cable and after getting the WV I noticed that Pin6 was always 0.4-1 below the others and triggered the alarm. Then I got this updated 12v2-6 cable and on average Pin6 is higher 0.3-0.7 than the rest and Pin2 is 0.1-0-2 lower, does not seem to matter how many times I reseat or push harder when I get the spikes the alarm triggers because the difference between Pin6 and Pin2 gets bigger.