Can’t connect to Garmin Connect IQ

For 24 hours now, I have been unable to login to Garmin Connect IQ. I use an iPhone and Venu device and am based in the UK. 
every time I try to connect using th App, I select my account and press “continue”. I then click the boxes to agree to the EULA and confirm that I’m 16+ years old. I then press next, but every time I am sent back to the Welcome screen. 
I’ve tried uninstalling and reinstalling the App; disconnecting my Venu; rebooting it; restoring to factory settings but I can’t get the App to connect.