Mitch_s_s wrote
My PC is wired directly in to my main Deco and has internet access, but the devices wired elsewhere don't
I initially tried wiring in my Raspberry Pi with Pihole to the main deco but that wasn't showing as being connected either.
@Mitch_s_s
If you can figure why wired PC is getting IP address from Main Deco, but wired Raspberry Pi with Pihole can't - you may be able to fix all your home network issues. Obviously, unless you accidentally blacklisted Raspberry Pi in Deco, they both should get connected - unless Raspberry config prevents it (static IP address, etc., etc).
Here is another test you can do: bring one of Satellite Deco to where your PC is, and wire PC to that Satellite Deco. If that works, it'll tell you that Satellite Deco Ethernet port is OK, but there could be something wrong with configuration on your devices that can't connect to same Deco by Ethernet cable.
If you can't figure the cause, try more drastic method: change ISP router back to router mode and switch Deco mesh to Access Point mode. In that configuration, Deco just broadcasts WiFi signal, ISP router manages your home network. If in that setup all your devices still can't connect, that won't be because of Deco mesh configuration. If they can, write down principal config settings of ISP router, such as DHCP IP range, IP subnet mask, etc. Switch back Deco mesh to router mode and compare same settings in Deco router.