Hello   @Jes_Olsen

Please check could other network devices get internet from Wi-Fi network of powerline unit? 

If powerline kit are paired (House Leds are ON)  but none of the device gets internet, you could try some suggestions here:
1> change a different Ethernet cable between Main router and main power line adapter
2> try a different LAN port on main router.

- Check if other devices use the same Ip address , you could try to change to a different IP  like 172.16.12. 240 for power line adapter 

If still the same, can I know your network topology like:  Router Archer C7 ( 192.168.0.1 ) ----PA8010P............ WPA8630P? can i have photo of IP settings on WPA8630P?