Alternative page-up/down keys don’t get forwarded

[fbruetting]

Fedora 34
Tilix-Version: 1.9.4
VTE-Version: 0.64
GTK-Version: 3.24.29

I use the german alternative keyboard layout Neo2, which provides additional key combinations for certain actions. When I press the modifier-key to get into layer 4 and then the key for either page-up or -down, the Tilix buffer gets scrolled instead of the content (e.g. less). Both GNOME Terminal and GNOME Builder forward the command to the currently running program. Would this be possible for Tilix, too?

showkey shows the exact same keycodes for both variants in both aforementioned programs, but Tilix handles the action and scrolls the buffer with Neo’s additional variant (and therefore prints no output for the alternative keys).

^[[5~ 	 27 0033 0x1b
 	 91 0133 0x5b
 	 53 0065 0x35
 	126 0176 0x7e
^[[6~ 	 27 0033 0x1b
 	 91 0133 0x5b
 	 54 0066 0x36
 	126 0176 0x7e