Xfinity Internet Issues

Today my internet began to act up. I have the 2.1gbps plan. My wifi speeds on my phone are around 270mbps down and 250mbps up which is "okay" but shows some high ping. Ethernet is where it gets weird. Speed to gateway bounces from 6mbps to 0mbps (not sure how the wifi is surviving if the gateway itself isn't receiving the speeds). On my PC with ethernet im getting around 5mbps down BUT still getting 350mbps upload. I have a technician scheduled today but im wondering if there's anything I can try to fix it sooner. So far I've tried restarting the gateway through the app, and disconnecting / reconnecting cables.