"Calendar for scheduling Relationship Lag" reset to Predecessor Activity Calendar every time when Co
P6 Client doesn't retain the "Calendar for scheduling Relationship Lag" setting when schedule has different than default setting.
When your schedule has different than default "Predecessor Activity Calendar" setting for "Calendar for scheduling Relationship Lag" P6 doesn't retain it when copying or making reflection of the project.
Tested on P6 Client version 8.3.0 / MS SQL 2005 and P6 Client Version 16.1.6 / SQLLite.