This issue is to release note the known issue in https://issues.redhat.com/browse/QUARKUS-1268.
Notice the suggested workaround mentioned in https://github.com/quarkusio/quarkus/issues/20066#issuecomment-925790012.
See:
This could be a bug in the original feature when handling quarkus.log.level specifically. If you use a category, then this works. E.g.
quarkus.log.category."io.quarkus.ts.logging.jboss".level=TRACE