P006, P007, P023 Cannot reconnect my 5 v2

[Meta]

So I have new modem/router/provider. Set the wifi up with the same SIDD name/password. Everything in my complete home network is working fine. Was looking at MAC adressess and 1 was off from the product info on 1 NP.
So I removed it to see which MAC disappeared to know which one it was. From there on HELL for days...

Did all things I could find online, chatted with support for a couple of hours to come to the conclusion that it was broken and I would get a new one. Strange, but fine for me....

Still setting up my new home wifi, I added a router and some repeaters. Still no single error of my home network or any connected devices/systems. Except now all (4 remaining) NP's are offline 

Same **bleep** again. All throwing Wifi connect error codes P006, p007, P023 at random, but mostly P007.

Things I tried with all possible combinations (not necessarily in this order):
Factory reset NP
Used the key instead of QR-code

Deleted all secondary routers /repeaters
NP and phone within 30cm of router
Phone restart/router restart
Reinstalled Nest app
Deleted all NP and Factory Reset them all
Deleted all homes in NEST and Home app
Changed to all different kinds of wifi password protocols
Made a guest wifi with different name 
Made wifi without password
Used another phone
All other wifi connected devices still 100% working without problems.

So I think I can conclude my hardware/wifi is fine and the problem is 100% the NP.
Searching goole for these error codes gives me no hope....

[Meta · Accepted solution]

After hours of chatting with support, it is finally resolved!
I had to open ports on the modem. They asked me to open port 11095 but as this was new to me I had to go trough the manual to look up on how to do that.
I first got to the UPnP port settings. 
Put it "on" and I could connect my Nest Protects!
Afterwards put the UPnP back to "off" and all is working again.

[zoeuvre]

Hey there,

I'm glad to hear that everything has been sorted out. Please let me know, as I would be happy to assist, and answer any questions you may have.

Thanks, 

Zoe 

[zoeuvre]

Hi there, 

We haven’t heard from you so I'll go ahead and lock this thread in 24 hours. If you run into any more issues in the future, please feel free to create a new thread.

Regards, 

Zoe