oracle 18C - setting db_files parameter at PDB level

Hello ,

Regarding db_files limit setting at PDB level. From 12c we can set db_files limit at every individual PDB level which is more than the limit set at CDB level.

Am currently working with 18C version (18.3.0) where db_files limit is set to high at PDB level to accommodate more datafiles. Post that when i try to add datafiles at PDB level the limit is being inherited from the db_limit set at CDB level and throwing an ORA-00059: maximum number of DB_FILES exceeded. My query is if we can able to increase the db_files limit at PDB level ( i.e more than that of CDB level) why it is still taking that from CDB level. Do we need to set any additional parameters at PDB level to get that work