Ethernet Is Slower Than Wifi

Laptop: Dell XPS13, model 9360;
Modem: Netgear CM1100
Router: TP Link AX50
Xfinity, Extreme Pro Tier, rated 900Mbps

My laptop is hard wired into the router, which sits about 4 feet above my desk. My service is usually trouble free, and my ethernet connection will usually clock in at about 925Mbps according to Speedtest.net. Wifi speeds are usually between 300-350Mbps throughout the house. In both setups uploads are a consistent 24Mbps.For the past week or so my ethernet speed is running between 125-200Mbps, while Wifi remains at its usual speed. With my limited know how I have done the basics: powered off modem and router multiple times; swapped out the cable between the laptop and router, same results; plugged in a second laptop, same results; wired laptop directly into modem, same results. (If it matters the WiFi card is an Intel AX200.) The connection between the router and laptop is with a USB-C to Ethernet adapter. Since I don’t have another adapter to test, I don’t know if this is the issue.  As I said, with my limited know how I’m pretty much stumped. Suggestions? Appreciate the help!