Auto refresh formatted search is an excellent way to customize SAP Business One but it does have its limitations. One of those limitations is when using the Copy To functionality going from one document to another. After investigating it is apparent that it simply does not work.
When using the "Copy To" function, SAP has background processes that draw up the document and display it 100% complete. The way SAP handles this scenario will never trigger the formatted search regardless of what field you choose to auto refresh upon. The Business One SDK is the only reliable way to fix this by writing a small add-on.
You might suggest to your users that using "Copy From" is a much better course of action. Users may also click the magnifying glass icon or hit SHIFT-F2 on their keyboards to trigger the FMS manually.
Using "Copy To" with auto refresh formatted search is an unfortunate drawback to a extremely powerful SAP Business One customization tool.