Are you using the 2.4 Ghz or the 5GHz network ?
The 5 GHz network is faster but it's more easily blocked by walls or any other physical barrier between the router and your device.
You should get a stronger signal on the 2.4 GHz network but the speed will be limited to about 70-80 mbps on a good recent device.
Same problem on either 2.4 or 5ghz, the 2.4 ghz is even slower, next room isn't far ! only 1 wall seperation and about 15 meters only, 80% of wifi strength is wasting half the 5ghz speed, same for the 2.4, should I change the router?
would the new router be easy to install ?
I understand the difference between 5ghz and 2.4 but I feel like the router is bad because sometimes I have to disconnect my device and reconnect it to get my connection back..