Add an environment variable to you run environment. Add TF_LOG and set it to true. Scroll through and look for an oauth api call. Look at the resource

I have run into the same problem, and it looks our appreg for  AzureDatabricks enterprise application is in a different tenant from the rest of our environment.

example:

[DEBUG] provider.terraform-provider-databricks_v1.72.0: GET /metadata/identity/oauth2/token?api-version=2018-02-01&client_id=<*****************>&resource=<*********************>

That's when searched for resource=<*********************> in EntraID, and found the app reg missing.