Image Freezes a fraction of second

Hi,

I've read many posts dedicated to freezed screens but no one similar to what's happening to my gamers.

I have 3 gamers , a first one, equipped with a RTX 4070 on a static rig, a second one, equipped with a RTX 3090 on a 5 DOF dynamic rig and a third one, equipped with a RTX 4090 also on a 5 DOF dynamic rig.

Whatever the gamer, after I start a race with IA (and whatever the number of IA), after exactly 90 minutes of game, I start have images "freeze", first, a very fraction of a second every about five minutes, then their frequency increases, the freezing time also but always less than a second. Half a second is enough to send you out of the track when you at driving at 250 km/h in a series of turn like at the end of the Le Mans track.

What is weird is that, I did the experience half a dozen times, the first freeze amlways occurs after the same delay: 90 minutes.

Given it occurs on three different graphic cards, it calls for an issue not related to them, but who knows, a generic issue for RTX cards ?

Did someone around there ever experienced such weird phenomenon ?

That you for any help, comment or advice.

Cheers

PS: English is not my native language.