@Bilal Aslam​  I didn't think to look there before since I hadn't tried to run any queries. I see the failed SHOW DATABASES queries in history and they identify the error:

Builtin jars can only be used when hive execution version == hive metastore version. Execution: 2.3.9 != Metastore: 2.3.7. Specify a valid path to the correct hive jars using spark.sql.hive.metastore.jars or change spark.sql.hive.metastore.version to 2.3.9.

My Data Engineering clusters are running the 9.1 LTS runtime and it looks like SQL is running 10.0.x-photon-scala2.12. I updated my SQL Endpoint spark.sql.hive.metastore.version setting to 2.3.9 which fixed the issue. Thank you!