ANSWER: I worked with the client to determine the issue was that the DB user did not have the requisite db_owner permission.

According to the Umbraco Documentation :

The database account used in the connection string will need permission to read and write from tables. It will also require permission to create schema during installs and upgrades:

The db_owner role has full permissions on the database.

To use an account with more restricted permissions, the db_datareader and db_datawriter roles will be needed for normal use to read from and write to the database. The db_ddladmin role, which can modify the database schema, is required for installs and upgrades of the CMS and/or any packages that create database tables.

I encountered a similar issue with an Umbraco 13 project. The solution was repeatedly displaying the 'Install Umbraco' page. Initially, I didn’t have the necessary database permissions, but it started working correctly after updating the database login user permissions.