After trying to run TPX on a second LPAR, even though the second started task was stopped, the APTPX VTAM task was active on both LPARS.
When I varied the non-production APTPX task inactive, the non-production LPAR instantly became available.
I need to understand why this happens and how to prevent it.
This WILL cause unpredictable results, since there would be multiple LUs with same name in the network. You can only have one node activate on one host at a time unless the LU names (APPLs in this case) have symbolic that would make them unique on each host.