@Crystal96 Looks like there was intermittent issue while creating the resource as I can see that the resource creation was failed due to backend issue and it failed with the error InternalServerError. I couldn't observe the same issue now. Please retry the operation and confirm if you are still facing the issue.
If you have any feedback/issue regarding Microsoft Learn then I will suggest you to report feedback scrolling to the last on the troubleshooting know issue article.
As Microsoft Learn is currently not supported in the Q&A forums, the supported products are listed over here https://learn.microsoft.com/en-us/answers/products (more to be added later on).
Sandbox FAQ: https://learn.microsoft.com/en-us/learn/support/faq?pivots=sandbox
For troubleshooting know issue you can refer here: https://learn.microsoft.com/en-us/learn/support/troubleshooting