Thanks Chris,

you're right, I found my mistake: I had a file in the classpath with the same name of the one contained in the jar, so it was loading that file instead of the one in the jar.
I just changed the name of the file and then I've been able to reproduce that issue. I also checked that the fix you suggested works perfectly.

I pushed that fix on the master (but using my test since it is a bit easier and doesn't require a change in the pom.xml) and backported it to the 5.4.x.

Mark, should I backport it to other (older) releases?

Mario