Tried to replace realm which failed and now 'unable to connect to realm'

I downloaded a backup world from my active realm and then tried to replace the current realm with it. It kept coming up with 'export in progress 0.00MB' (see Image.1) and then it would just fail. I gave up after trying multiple times (each taking upwards to 30-60 minutes before it failed, please see the image '2.jpg') and tried to join back into the realm, which resulted in me not being able to play across two devices (please see image '3.jpg).