Question about Devolo Magic 2 LAN Starter Kit 1-1-2

Hi I am sitting about 10 metres away from the router. With LAN cable, directly connected with a 15 metre cable, I have a ping of 20ms. Now with these devices again just as bad as with the wifi and up to 60ms +/- 30ms. can anyone tell me what I'm doing wrong or if this is absolutely normal? because no one can play online games like this