Constant regular stutter with Geforce Now

I've got a fast connection, very low latency, GeforceNow runs with zero packet loss at 60fps and for every other game I play on there you can't tell that I'm not running it locally. I'm on a paid tier and in the game's Display Settings it tells me that I'm running on an Nvidia A10G-12. With FPS Cap switched off, it's running at around 100fps. But every 0.75 seconds or so there is a horrible judder. It is constant throughout the entire time I'm playing and it's bad enough to almost make me quit completely and try Lost Ark instead.

None of the graphics options makes any difference whatsoever. I've tried every single one. Even if I set the Foreground FPS cap to 10 fps, I can still see the same regular stutter. It's just horrendous.

Is there anything that can be done about it? It only seemed to start happening about two weeks ago.

My problem has been solved and I'm now back up at a solid 60fps. Embarassingly, all I had to do was reboot the router.