Change of Admin Password from "test" results in IDM redirect loop.

After updating the admin password using the IDM UI, and editing the admin.password setting in all of the properties files and codebase, I am no longer able to login to any of the services other than IDM user manager.

Modeler and Task apps both redirect to the login screen on IDM:

http://localhost:8080/flowable-idm/#/login?redirectOnAuthSuccess=true&redirectUrl=http:%2F%2Flocalhost:9999%2Fflowable-task%2Fworkflow%2F

Sadly after changing the password back to "test" in all the places, it now does not work with "test" anymore either.

Is there a persistent store or secret cache of credentials or some other secret at work here? What is the official procedure for updating the admin password to something secure that will work?