Starting with 18c is possible to duplicate one PDB from an active database. This is a cool feature that helps a lot in daily activities. But recently I got one error when the destination is using ASM, and the files (of course) are managed using OMF. The solution is simple and is related to a bug that is affecting the 18c, 19c, and 21c versions.
Duplicating pluggable databases can be done for a long time and have some rules. But the duplicate PDB from an active database to a new CDB helps a lot because everything can be done online. We don’t need to create an intermediate CDB to export this PDB doing the unplug/plug, or cloning the source locally to read-only PDB and create a new one using dblink, or even using rman backups.