This is a classic case of an encoding issue. If you are displaying using a different encoding than the one you used when saving the date, a problem like this can occur.
In terms of Hibernate changes, I don’t think there’s anything that could trigger this change. You said you upgraded Wildfly from 10 to 14. But the issue can come from the web layer. How did you come to assume this was a Hibernate problem?
The only way to solve it is to use the same encoding across all layers: browser, web application, database.