I have an M1 Macbook Pro and a thunderbolt dock, and I am suffering what seems to be a reasonably normal experience of often-poor net connections:
My dock (a CalDigit) doesn’t have its own WiFi chipset (quite reasonably – what am I going to plug into it that doesn’t have its own?) but it does have an ethernet socket. My home office has no ethernet.
But it does have a Raspbery Pi in a box. I installed Raspbian on it and ran the same-subnet script here:
I’ve tried a few times to fiddle about manually to get this to work, and remembered why I refused to become a network guy. That script Just Worked for me, behind a Sky Broadband router.