Firstly, please check the IP address on the laptop, since the powerline adapters has been connected with the middle light lit up, you need to make sure there is an IP address, if no, give a try to...

Well, in that case, I can only assume that the modem may be faulty... Maybe you can take the product back to the shop and see whether they can help

I may suggest there might be something set on the computer blocks the Home PC from pinging by other clients, since the firewall has been turned off, maybe you can check the settings for the...

They all belong to Homeplug AV

If the models belong to the same Homeplug Standard, they are compatible. For example, TL-PA210, TL-PA211, TL-PA411，TL-PA511, they are compatible with each other.

Maybe you can try to reset it to factory default settings and see whether that helps or not.