The default config script is not helpful, as it does not reproduce the situation that brings to the broken URL. My speculation is that this has something to do with the way host and port are configured on the instance that is "misbehaving". The URL ends up with an invalid ":" at the end, which is at the core of your problem, and you should try and find out why.
Concerning new and existing issues, please report them in the bug tracker, if you did not already and we will try to address them. If they are severe enough, they might be fixed before the 5.10 release.