UK Passport - Ask someone to confirm your identity

Hey,

So I've just submitted my application to renew my passport a few hours ago. I go to submit the details of the person who's confirming my identity and I get this message: 'Sorry, this service is unavailable
You’ll be able to use the service later.

If you gave any answers, it wasn’t possible to save them. You’ll need to start again when the service is available.'

Is anyone else having this issue? Any idea when it'll be fixed?

Update - there appears to be an issue with Google Chrome, but Microsoft Edge works perfectly with this part of the application.