No push notifications when connected to wifi

[GnortsMrAlien]

Hi ,

I have a ZTE MC801A router which i recieved from three when i signed up to the 5g hub internet when i moved into my new house. Since then i have not recieved push notifications through to my phone, neither has my girlfriend. When we disconnect from the wifi and to 4G roaming we recieve all the notifications we should have at once. This also means our Google Hello doorbell does not work - it does not send notifications through on home when we are connected to wifi and also means we do not hear the doorbell as it wont send a chime through to the Google Mini speaker. Ive tried port fowarding Port 5228, reset to factory settings, enabled UPNP and reset the Google Home devices with no luck.... Any idea? 

[crypt0ninja]

Hey @GnortsMrAlien to add to the good points @JonathanB has mentioned above, can you also confirm which APN your MC801A is using?

Is it using the 'three.co.uk' APN or '3Internet' APN?

You want to be using the 3Internet APN for any Port Forwarding/uPnP etc. to work as the three.co.uk APN uses CGNAT (Carrier-Grade NAT, it puts many users behind 1 IPv4 WAN IP address rather than allocating each users their own IPv4 WAN IP and can cause such issues as you describe).