When impersonating the Walk-up user in the walk-up portal and trying to click the locations reference field, it is stuck loading infinitely. The user wanted to know why this is happening.
It was found that the user had customized the Table API ACL:
Walk-up Experience is a very secure plugin. This means that everything was designed with security in mind. As such, the walk-up user has roles that were given them by design, and they cannot/should not be altered.
Because of this, it is necessary to impersonate a specific user (walk-up user) to have the Walk-up Experience work as expected.
So, what is happening here is that when the Table API ACL, which is active = false Out of Box (OOB) is installed, the walk-up user fails the role check on that ACL.
The walk-up user cannot (and should not) be given the role associated with the ACL, hence they will always fail it causing our location reference field to load infinitely.
Reverting the ACL back to OOB (active = false), and clearing the cache (a crucial step to make this work, as ACLs cache), allows the walk-up user to see all locations almost immediately.