With the update of Mojarra in JBoss EAP 8.0 Update 3 the response character encoding is broken.

Attached is a (pre-build using Java 17) reproducer application jsf-encoding-reproducer.zip.

Opening the application with http://localhost:8080/jsf-encoding shows a simple form, see:

After click here is pressed, the wrongly encoded output can be seen inside the browser, see:

This was working fine until JBoss EAP 8.0 Update 2.1.
 
We returned back to standard behavior by https://issues.redhat.com/browse/JBEAP-28883

Unfortunately this is not 100% correct behavior like is described in the EE specification.
https://jakarta.ee/specifications/faces/4.0/jakarta-faces-4.0#determining-the-character-encoding

When the page is not re-loaded and is clicked on the button. The character encoding is broken.

When the page is re-loaded and then is clicked on the button. The character encoding is correct.