I was using my Fire Stick (basic, not 4K) for about 3 months in a room closer to the router. Not a single problem there, never lost connection. The same day (just 2 days ago) I moved it to a different room, which is a bit further away from the router, these problems started. Signal strength is still very good (around 50 dBm, never over 55 dBm), but not as good as at its original location, where wifi signal is in the low 30 dBm. I had to move my Fire Stick here, because of issues that started showing on my Apple TV, as explained in the original post. Whatever channel my router is using, it is the same as it used to be, when Fire Stick did not have any problems. The only thing that changed is that it now works in the area where the wifi signal strength is in the 50's, instead of 30's dBm. 50-60 dBm is still considered to be a very good signal, but it appears that the Fire Stick does not think so. I am afraid that the only solution I have will be to somehow boost the wifi signal. I have an old Linksys router somewhere, so maybe I'll try and see if I can use it as a wifi repeater. Frankly, I don't think that the wifi antennas in this Fire Stick are that great.