Disconnecting

There is this weird thing going with the thing, for example when on FaceTime doesn’t matter how long into the call but it’ll kick me off the connection and force me to switch to LTE and drops the call and when that happens I’m connected like nothing happened. And earlier today the upstream light started blinking (still green) and when I seen that I ran a Speedtest and it failed I tried to find some answers on reddit contacted my ISP (which is Spectrum), reset the thing, shoot I even went as far as blaming my phone and got a new one still nothing what can I do?