[HELP] Remote play from home - "Searching via internet"

Hey all!

I'm the proud owner of my 2nd vita. I owned one on release but sold it.. but I decided it's time and went all in.

I bought God Eater 1+2 on the Vita + PS4 for Cross Save. Persona 4. I'm ready :)

I bought myself the Aqua Blue Japanese Import Vita Slim. I love it!

Now.. here's my question.

I have my PS4 Remote play set up with my secondary PS4 from within the home. It works great over WiFi. The reason it's on my secondary is that is MY console, but my girlfriend has my account as primary on her PS4 for game sharing, within the same home.

So I manually added the code and set up with my Secondary PS4 - so I could stream my titles.

Now that I'm out at work - I'm trying to Remote Play.. but it isn't working. It just says "Searching via Internet".

Does it 100% HAVE to be the Primary PS4 if I manually set up the Secondary?

Is there something I'm missing?

Just a heads up, my internet connection is solid - 353/23 Speedtest.

Thanks! :)