Remote play woes

Hello,

Got a really annoying issue with remote play.

In the past I’ve been able to use my phone as a hot spot & then use my windows tablet to connect & let me remote play.

Recently it’s been more miss than hit. Got a connection a few times but I mostly get the 80001fff.

I can see the remote play wakes the PS4 but does when checking environment.

If I connect via another network say a friend or family’s WiFi . The. It works with no issues.

My phone has a good 4G connection with full signal strength.

Used to work with no problem but no it gives me grief.

Could it be a port issue with my cell connection?

Thanks