2080ti KP +5V too high

I'm not using extensions; I'm using corsair-brand cable set approved for my specific corsair PSU. 

In that thread you stated the standard is 5.25V, 5.35V max; mine is ~5.18V at idle and ~5.28V once [link=mailto:F@H]F@H[/link] starts with peaks up to 5.4V. I took a video to watch it. I don't know when the KPE decides to display the 5v warning but in my video I never caught the reading above 5.4v. 

In that thread you recommended measuring the voltages manually. I checked the short KPE manual and this xdevs guide but I don't know how to measure the 5v myself. It looks like all those probeit ports are for ~1v stuff otherwise that would've been really convenient :/