Unstable Upstream/Internet

Hello, ever since 11pm on June 2nd my internet has been very unstable. I'm currently using a Netgear Nighthawk CM2000 modem paired with a TP-LINK Archer AX11000, however download and upload speeds seem fine but both have a large ammount of jitter and latency. Any internet communcation or gaming is virtually not possible. My modem page says there is a upstream problem. Also the xfinity app shows all of my equipment is offline, when it isn't. Anyone else ever experienced this? And if so, any advice? I'm thinking a splitter is failing. Thanks!