Past week or so random internet connectivity to devices issues

My router connects to the internet and usually has 3 bars on it which is good internet connection, but my devices won’t connect at all or sometimes they connect in and out within seconds, i have tried disnonnecting the router and trying it after a few minutes but the problem persists, i have the white router which is 5G, anyone else had this issue and maybe know what the problem is? my router is close to a window and in the middle of my 3 level townhome.