I second trying u/wase471111 and u/leewhat’s suggestions, especially getting the router off the floor and near the ceiling. Even moving the router from side to side can make a difference. The physical materials the signal has to pass through and interference from other devices can drastically reduce the quality of your wireless signal no matter what router you have. The wireless radio and antenna built into the devices you’re using in your problem room also make a difference. If the problem is interference changing the channel your router broadcasts on might help.

Asus. I use Merlin’s firmware and there are others available if you don’t want stock.