@rustyshackles I figured it out. I was doing setCurrentSublistValue from within validateLine, which triggered fieldChanged, which triggered validateLine, overwriting my previous change. I add a commitLine during fieldChanged and that fixed the overwriting but now it adds an extra line at the end during the second validateLine.

If you use nlaiSetCurrentSublistValue, there should be a function parameter that you can set to false so it does not trigger the field change event. I think the parameter name is fireFieldChange, but you can double check in Help.