I've recently changed to a new ISP and am experiencing very high ping in-game with the new connection. I've previously used GFN on hotspot, which still works fine. I don't believe I have this ping issue anywhere else - League, Stadia (rip) all work fine. I've tried a couple of server locations and streaming qualities, but the issue persists (and the ping is fine regardless of the settings when using a hotspot, which leads me to believe the issue is elsewhere).
The ping looks fine when doing a network test, but spikes up within seconds upon launching a game and stays in the 800-900 range.
Any help or advice would be much appreciated, I haven't seen any issue like this when searching for a solution.