This might be connected to how the new flow builder works. Using the old builder, I can open the power query editor and can see data queried from the database (still won't work tough).
Using the new builder however, I get an error after typing in the SQL query:
Failed to retrieve dynamic outputs. As a result, this operation's outputs might not be visible in subsequent actions. Error details: The dynamic operation request to API 'sql' operation 'SqlGetPassThroughPQMetadata' failed with status code 'BadRequest'. This may indicate invalid input parameters. Error response: { "error": { "code": 400, "message": "Error while processing request body: Unexpected character encountered while parsing value: s. Path '', line 0, position 0.", "source": "default-b42.....01.common.europe002.azure-apihub.net", "path": "choose[10]\\when[1]", "policyId": "", "clientRequestId": "b7...", "dreeSet": "true" } }
Power platform community thread: https://community.powerplatform.com/forums/thread/details/?threadid=66a0da9c-9e9f-ef11-8a69-6045bdee0f9b