Have 2 Roku TV’s - one keeps disconnecting from the wifi

They are both the same model, purchased one year apart.  We need to reconnect the tv to Wi-Fi every time we turn the older set on.  Our Wi-Fi is not great, live in a very rural area that has limited reliability.   If the Wi-Fi goes out while we are watching (say, for a minute or so), the older tv has to be reset up again.  The newer tv patiently waits and when the Wi-Fi is back up the new tv starts streaming again.  The older one totally stops, and when the Wi-Fi is back up may or may not connect to the Wi-Fi.  We get these error messages that make no sense since the newer tv is working fine at the same time.  We know we don’t have restart the modem.