Recently swapped from win 10 to manjaro but i’m constantly having network issues were i can only open certain webpages (ie the manjaro websites and YouTube) i get these same problems when not using Ethernet instead using wifi and i even have these problems with application (ie steam cant connect to update).
The reason I ask is because I experienced a very similar issue to what you are describing when using Netgear PowerLine extenders. (I’ve since sold them on eBay and went with something else.) It could be an entirely unrelated issue with what you’re facing, however.
I meant using the PC’s built-in WiFi (Intel, iwlwifi) to connect to the router, even if it’s a “weak signal”, it’s just to test something out as a process of elimination.
Manajro Settings Manager > Hardware Configuration > then you should see an option to switch to it. (I’m going from memory here, so I could be wrong. I believe it automates switching over to r8169 by modifying a blacklist entry for a .conf file under /etc/modprobe.d/ )