Hi John,
try changing the location param from:
param location string = resourceGroup().location
to: (region is an example reference)
param location string = ‘uksouth’
Then try the deployment again? It’s possible the region is causing an issue but I’m not sure where your resource group is deployed to. Try with a different region like above just to test.
let me know how you get on. If it works I’ll convert this to the answer so others can benefit.