Pixel 3XL won't connect to WiFi or mobile network. Help!

[Android Central Question]

I am travelling overseas and my phone suddenly stopped being able to connect to both wifi and its mobile network.
I have a 3 UK sim and my own Australian sim - both of which were working until last night.
I cannot find a single wifi network even though on my laptop I can see plenty and am easily connected to one now. The wifi icon just has a question mark over it.
I cannot connect to mobile data or network using either of my sims. Both of them have plenty of credit/data. Mobile roaming is definitely switched on.
I have tried the following:
- changing sims
- the reset WiFi, mobile and bluetooth function
- restarting my phone in safe mode
- full factory reset of my phone (I am devastated because I have lost all my recent photos - since the phone couldn't connect to backup).
I have tried to contact pixel support - but of course the primary way of doing this is via the device itself, and with its connectivity issues this won't work.
So now I am stranded overseas without any connectivity - not to mention my phone had a lot of my trip info saved.

 

[B. Diddy]

Welcome to Android Central! Ugh, that sounds very frustrating. Try contacting Pixel Support on a computer browser: https://support.google.com/pixelphone/?hl=en#topic=7078250. Click the Contact Us button at the upper right to request a call or chat. Offhand, I'd suspect either some firmware corruption or hardware failure.