It is a strange one
I'd still troubleshoot from a m8's house as if it works you'll know it isn't the settings. If it doesn't then you can start pulling the network apart
might be worth checking the logs on the ps4 under remote play settings and see if there is any activity round about the time you tried this aft!
might be worth checking the logs on the ps4 under remote play settings and see if there is any activity round about the time you tried this aft!