I've got many same errors ldap-rc=21 on subcriber status log. Found
TID10095847 similar symptom. Follow the instruction here to replaced
Output Transformation policies xml which copy from this TID and removed
from Input Transform SS. Error still occurs. In this TID, it mentioned
"Also chain it in the Publisher on the Input Transform Policies AND also
have to remove the following from the existing Input Trnasform SS..."

I only removed, but any action I need to take for CHAIN IT IN THE
PUBLISHER ????

Or any other solution ??