Stock router... I'm also having bad experience with it. My toilet is like 10m away from my room, cannot load pages anymore when I'm in toilet though I'm connected to it and it shows full bar WiFi.

Once I get out and approaching my room's door then pages start to load again.

This should be router issue right? Any other possible reasons?

yeah bro..the stock router is the worst i have experienced..random disconnection of the wifi,slow download rate,sometime need to restart because no internet connection.. what model of asus router do u use now bro and how its performance like range,speed?is it better than ur tp-link?