Having trouble duplicating this.

The first time you print, is it possible you are using the Preview button first and then clicking on the Printer icon from there to print a hardcopy? If so, the status will always remain Open.

If you are printing using the Print button on the print window but have changed your Print Destination Options to 'Screen', the invoice's status will also remain Open -- unless, within the Company Profile on the Print/Post tab, you have turned on the 'Mark printed to screen as printed?'.