Problem with ALV + PDF display in SAP GUI HTML

hi there,

i have a Z-program which displays an ALV (OO) grid. then i have a button to display an PDF in an internet explorer window for each row in ALV.

this is working perfect in "normal" SAP GUI: i select an row, push the button "Anzeigen/Drucken PDF" ("display PDF" in english language) and seperate window is opened and displaying the PDF:

now i need to implement this report in nwbc via SAP GUI HTML. when starting this report it looks like this: i have the alv grid displayed:

BUT: when i push the "Anzeigen/Drucken PDF" i get the following: the PDF is displayed in seperate browser window correct ! BUT the ALV grid disappears and there is only a white page displayed. i have no idea why this happens in sap gui html.

here is part of the coding which opens the window for displaying the PDF. i have played around with the html controller and the container. But everythime it is working for "normal" SAP GUI, but NOT in SAP GUI HTML.

any ideas ? 😊

br Martin