Resolution
1. Get subscription ID for the affected Plesk domain in PBA-S database 'aspc':
mysql> SELECT s.subscr_id\
FROM subscr_pleskdomain s, subscr_pleskdomain_perms p \
WHERE \
s.subscr_id=p.subscr_id AND \
pd_hostname='PLESK_DOMAIN_NAME_HERE' AND \
perm='manage_drweb';2. Enable the permission 'manage_drweb' in the table 'subscr_pleskdomain_perms':
mysql> UPDATE subscr_pleskdomain_perms \
SET is_enabled=1 \
WHERE \
subscr_id=SUBSCR_ID_HERE AND \
perm='manage_drweb';3. Enable corresponding permission in Plesk server:
# /usr/local/psa/bin/domuser.sh --update DOMAIN_NAME_HERE -manage_drweb true