@Yannie Hie Panda, thanks for the link and i would be happy to buy a little (and use the software controller) But since i don't understand the problem, i think more knobs won't help. I am quite sure...

Apologies for my low level of knowledge* I plugged in the er605, a couple of modems and by now 20-30 access points (archer 50's and wr8000), reusing the old cables that were still in the house when...