Since a Plesk node was registered in OBAS, all operations with its clients and domains should be performed through OBAS (PCC/RCC/CP). Resources modifications through Plesk might break synchronization with OBAS.
How to forbid clients to modify their domains/clients through Plesk?
To prevent customers from modifying their domains through Plesk you may deny administrative access to the panel:
Plesk > Tools & Settings > Restrict Administrative Access
Click "Add New Network" and add your IP Address and IP Address of OBAS node.
Mark enabled "Denied from the networks that are not listed" and click "Set". With such configuration customers will not be able to login to Plesk for management of their domains - they may be edited through OBAS CP only. Remember to add IP Address of OBAS node to the list of allowed IP Addresses - this is required for domains management through OBAS.
Just for your information: Plesk access policy is stored in table misc of Plesk database:
Policy "Denied from the networks that are not listed":
mysql> select * from misc where psa.param like '%access%'; +---------------+------+ | param | val | +---------------+------+ | access_policy | deny | +---------------+------+ 1 row in set (0.00 sec) mysql>
Change the value to "allow" to switch to policy "Allowed, excluding the networks in the list."