Working on Windows 10, the default printer is changed when the application closes and the runtime is shut down.
For example: the default printer is set to PRINTER1.
The COBOL program sends a print to PRINTER2.
After the run, PRINTER2 becomes the new default printer.
This never happens on Windows 7, where the system settings remain unaltered.
This appears to be a "new feature" of Windows 10, rather than an issue within the ACUCOBOL-GT runtime.
Some versions of Windows 10 have a switch called "Let Windows manage my default printer".
When turned ON, the last used printer will become the new default printer in the system.
Here is a link that explains this "feature" and how to turn it off:
Open Settings -> Devices -> Printers & Scanners (on the left side)
On the right side there should be a section that says:
"Let Windows manage my default printer"
with a switch that can be turned OFF to keep the default printer chosen by the end-user.