I've encountered similar problems earlier, usually rooted in some form of memory error or just an erroneous state. Wildfly might also be in a state where it is running but requires a restart. Such a state makes the "Wildfly running?" checks fail.
My go-to solution is to kill wildfly and then start it. Do it with a SIGTERM and check logs to see if wildfly starts shutting down. If not you may have to forcefully terminate wildfly with SIGKILL. Be careful when doing this. Although I have not run into any issues killing wildfly like this, forcefully killing a process does not allow time to shut down gracefully can result in dangling sockets and file handles which may interfere with the next startup.
