Can't get past the phone number entry for download. Any ideas?

I have tried multiple times to install InDesign. Yet every time my Creative Cloud bar opens, it asks me to enter my mobile number. My mobile number is already entered in my account info.

It simply refuses to let me skip this section, despite having a skip button.

I have input my number many times, using standard format (07764 etc) and international format (+44 7764 etc), played around with spacing etc. It constantly tells me the number is invalid, and, as above, won't let me skip this step.

Any ideas? I'm getting increasingly angry about this.