Posting change to transfer SO stock is incorrectly asking for a reason for movement

[BMJ]

When completing a posting change in EWM to move batch of 913108 from SO 5044582 to 5044581, the system would not proceed without a reason for movement being entered. 
Once entered, the Posting Change processed and updated in both EWM and IM - movement type 413.
A reason for movement was not required before - and should not be needed for this movement type

Attachment shows the error and the MB51 completed transactions after the reason for movement was added