Since installing Extended Terminal Manager (ETM), PF Key 12, produces a print of the currently displayed screen.
This PF key should not be mapped to any function as it is used by applications.
This problem only occurred after installing ETM and it's pre-requisite, IMS Extended Terminal Option (ETO).
The COPY/NOCOPY option on the logon descriptor controls whether the IMS Copy Function is allowed for a terminal.
If the Copy function is allowed for a terminal, then pressing the PF12 key will print the screen.
The default for the COPY/NOCOPY option is NOCOPY.
Check the logon descriptor parameters for these terminals and set the COPY/NOCOPY option accordingly: