That’s correct. I can post the amended drawing but every device (including the wireless router) except the modem is plugged into the 8 port switch i mentioned in my last post.
It is possible, though unlikely, that i have a bad copper connection somewhere. I have only added one Cat 6A cable to the system, but it’s to a different device (dock for a Steam Deck) from the switch.
I can swap the Cat 6A cable from switch to Infinity, and separately return the NAS back to its RJ45 connection, and see if any of those trials return it to the previous speed.
I figured I’d ask here first in case there are SW settings i need to change rather than equipment to check
I can post the results of any tests i run when i get home.
Thank you