av500 has HomePlugAV as their networkname maybe you should change it to whatever network name av1300 has. could be HomePlugAV2?

second picture should be the right architecture given you are only using a TL-PA4010P KIT which is capable of plc 500Mbps out of the box. maybe try to update all to the latest firmware.

@MWil try installing tpPLC to check your powerline networking. https://www.tp-link.com/uk/support/download/tl-pa8033p-kit/#Utility

@DanW if you are accessing the powerline specifically below should be default. user: admin pass: admin

I have a TL-WPA4220-Kit version 1 as a start then added the following: 1 TL-WPA4220 extender version 1 1 TL-WPA4220 extender version 4. Ive installed tpPLC android app in my phone i can only see the...