Wireless device out of range then has full signal after removing and readding

I have and android tv box that has been unplugged ofr a while. Plugged it back in this morning and would not connect to wifi. Kept saying it was out of range. I removed the saved wifi name and readded it manually and magically/mysteriously its in range with full signal.Box has always been 10 feet from the router and this is not the first time this has happened or the first device either.

Since this is not the first device, What would cause (ANY WIFI DEVICE) to say out of range (when it's really is within range) but want you do deltete your save info and readd everything again.

This is also not the 1st router this has happened on. The common between the 2 routers (Netgear WNDR3400 and TP-Link C7 Archer) is they have bothe been used as a DHCP server so my IPs stay put where I set them. Shouldn't matter because the router has it on a permanent lease. Or DOES it actually matter somehow?

Things ALWAYS work via LAN cord but on WIFI, eventually it's gonna say not in range until deleted and readded which makes ZERO sense since the 3 router antennas and 2 device antennas are only 10 feet apart.