This happened to me 2 years ago flying TPE-KUL on MH. MH gave an invitation to the CI Dynasty Lounge. I visited there first, then tried to go to the CX lounge and was denied, saying I could only visit one lounge per invitation. It would be really nice if Oneworld could add a list of exceptions to their lounge policy on their website, whether it be carriers or airports that have this one lounge per airport policy.