Thanks for the response, you may have missed that I have tried using a Deco in the same situation and it sees the speed drop as well.
I did check the Mac, it's an M1 Mini running 15.5. When I go into the settings for the ethernet hardware, it is configured automatically, but if I change it to...
Thanks. I can try to pick up another switch, may take a while as I don't live close to a store that has them. However, it's still odd that every other connection through the switch works fine.
I rent a house that was finished less than three years ago and has ethernet installed. I am running two Deco units on the ethernet plus the master Deco at the router, one Mac on the ethernet and one Deco with wifi. There is a switch, TP-SG1005D, after the main Deco that the two Decos connect...