I am having similar issues with dropping of connection or to less than 0.5mbps . This is happening on average between 5 to 10 minutes.
I am supporting school teaching at home, so would be good to have stable connectivity ASAP.
If you could do a line test and check the SNR settings. I am connected directly to the master socket. Appears to be a problem on both 2.4 and 5ghz WiFi networks. I don’t have an Ethernet port on my MacBook to try out and eliminate the WiFi .