Attached file "Security.ear" contains a web application with a single jsp page "index.jsp" and form based login, which is secured by a Database Identity Store (Elytron).

When calling the root URL of the webapp without specifiying any page and no trailing slash (http://localhost:8080/SecurityWeb), on WildFly 11 the login form is shown, and then the welcome file "index.jsp" is shown.
On WildFly 19, the login form is shown, and after successful login, there is an error message "404 - Not Found", and the URL in the adress bar changes to http://localhost:8080/j_security_check

It works if the URL is "http://localhost:8080/SecurityWeb/" (trailing slash). It seems WildFly 11 appends the "/" automatically when redirecting to the login form, while WildFly 19 keeps this URL.

To run the sample, you have to add the Elytron config - the script "configure.cli" can be used for this:
jboss-cli.bat --file=path_to\configure.cli
The script "restore-configuration.cli" undoes this configuration.

Username/Password are e.g. "admin"/"admin" - the sample creates a user table based on an ejb and "import.sql" inserts users.