@StefanJ If its TalkTalk on the BT network then the same will apply, Talktalk router first, with Decos connected in AP mode.

@jijookhier Did you enable the "Sync IPv4 account" switch as this should be enabled? Your screen snip shows it turned off. And "Get IPv6 address" should be "non-address"

@friedeggs Deco M5 is end of life, the only updates that will be pushed to the device are security updates if needed. https://www.tp-link.com/uk/home-networking/deco/deco-m5/

@StefanJ If its BT full fibre with Digital voice you are moving to then as far as I know the BT hub will need to be used in order for digital voice to work, if so then you could use the BT hub as...

@Nicj56 what settings have you tried? Try the below and see, this works for me with BT UK PPPoE and PD of 64.

@Jasper_Kimmel Yes this is possible, you would need to tell the new unit to only connect to the main Deco, this can be done in the connection preference settings on the Deco App.