Remember last row after closing window (Item tracking)

I cant figure it out, could you help me please?

Item tracking, when looking up a serial number F(orm)6510 calls in OnAssistEdit a code unit that in turn opens F6500.

In Nav 3.70, F6500 always remembered the last row chosen, you closed, went back to F6510, and reopened F6500 and the last row we worked with is already selected.

This functionality is not there in 5.0/5.1. I am trying to recreate it, but cannot see how to do it without sending the record as parameters forth and back. properties like savevalues and sourcetableplacement do not work as the form operates on temporary tables. Of course global variables are also gone when the form is closed.

anyone else interested in looking into it and giving me a hint how this remembering can be done?

I think, a better way to ask is: Does anyone know why sourcetableplacement=saved property does not work in Form 6500 in Nav 5.0/5.1?