Thanks for the suggestion, but it's more frequent than that. I've run the benchmark a few times and it seemed a bit better with DLSS off, but obviously the frame rate is much lower then.
I haven't had an Nvidia card for ages so wasn't sure if I was missing something obvious, or if it was a common problem. I might try and record it to show what I mean.
Otherwise I'm quite enjoying the game, it's so much better on PC compared to console and I think one of the reasons why is because some of the combat is so chaotic. It was just too difficult to keep up with and feel like I was.in control with a controller. The game looks amazing as well.
Edit: just seen a video on YouTube where MSI Afterburner/Riva Tuner are recommended to cap frame rates, rather than in game frame rate capping, as this produces more consistent frame times. Or something like that. Anyway, I'll try it later and see if it helps.