@DMS With Client Scripts you need to consider all scenarios, for example: • fieldChanged will trigger for any field change, therefore you may want to filter your fieldID as well as your sublist ID to make sure you are triggering your logic exactly for the field and sublist you want. • Another tricky thing for CS is the postSourcing event which triggers for lines sourcing values from another fields/records and it happens a lot. Recommendations: • Your if should include your sublist and field ID • Check what is happening in postsourcing.