Clarification on steps creating Database Replication Definition
step 1 not needed and not normally recommended as it can lead to contention issues on system tables

setp 3 is needed if you want to replicate DDL and system procs (which coincides with what you've got in step 4 - replicate DDL/sysprocs)

create sub should be step 5

check sub should be step 6

step 7 would be sending a rs_ticket from the PDB and making sure it arrives in RDB's rs_ticket_history table

make sure your maintuser (in RDB) is aliased to dbo to get around permissions issues