Thanks Dan - the issue is a “Failed Exchange” after a “Success Login”
This is happening for Chrome & Firefox (desktop).
I saw a similar issue reported for an Angular SPA app back in 2020 (Success Login and a Failed Exchange - #9 by sagun786), but I do not know where those configuration settings are stored. (I did a text search for “grant_types” and “token_endpoint_auth_method” in the React sample app, but nothing came up.
Is this a common newbie problem w/ a simple fix?