Hi @Kamal_Kishor
I faced a similar issue when migrating workflows to 6.5. Below points might help.
1. Make sure you are adding the entries in ui.content filter.xml.
2. Add the below filter in ui.apps.structure pom.xml
<filter><root>/var/workflow/models</root></filter>
or in your case
<filter><root>/var/workflow/models/<project-name></root></filter>
Let me know how it goes.
Thanks