Hi Oscar;
Unfortunately, the PrintScreen feature in PS2017 & PS2019 does not work well. Sometimes it prints a 1/2 a screen and sometimes you get an all black page printed. Sometimes you get an all white page printed. Seems to be random behaviour each time you print or switch printers (at least in my testing). The related open support ticket # is 2651 for this issue.
The Object.Print() feature that we have in a native PB App is not supported in PowerServer 2017 or 2019. That is well documented in the PS Help. However, it would be a really nice feature to have IMHO for our App users. I have already opened up an enhancement support ticket # 2682 for this feature .
Not all bad news though ... I have a workaround implementation for both the PrintScreen and PrintWindow features in PS Web Apps in my latest framework release. The framework allows PS Web apps to have both of the above features working in their Apps right now in either PowerServer 2017 or 2019. For more information, check out this link: http://chrispollach.blogspot.com/2019/05/ifc2019r2.html
HTH
Regards ... Chris
PS: I have an updated framework version to upload later this week that has some small PrintWindow improvements.