All other devices in our home are working perfectly with it. I turned it off and back on again, haven't done a pinhole reset. I haven't tried an ethernet cable but assumed (may be wrong) with two units doing exactly the same that it is a wifi issue.
I'd try an Ethernet cable before the pinhole reset as a wireless issue normally impacts most or all wireless devices. A pinhole reset will reset all wireless settings to the defaults, so if you have made any changes to the wireless settings in the hub they will be lost and you would need to change them again. If you haven't made any changes then there is nothing to lose with a pinhole reset.
It may be Sony are blocking your VM IP address, so when you go via your mobile it works. Are there any error codes on the PS4s when you try to connect? Can you login to the PSN via a web browser on any other device connected via your Hub?
My setup: V6 TV box, M350 Fibre broadband with Hub 3 in modem mode connected to a Netgear R7000 router. Telewest/VM user since 2001.
As a Very Insightful Person, I'm here to share my knowledge. I don't work for Virgin Media.