Symptoms
Domain's nameservers were not changed on registrar side when domain was transferred with EPPREGISTRAR C++ plugin.
Cause
The situation is caused by software issue #PBA-86011 . Contact your Technical Account Manager or PTA team to clarify the status of #PBA-86011.
Workaround
Update nameservers for domain manually with Billing > Domains > Your Domain > Manage Name Servers > Update Name Servers