I've never seen that.. 2 ideas..
check that the sub app is not on some layer with an x/y offset.
check the scrolling options for the subapp in the runtime options.
I've found the sub-app is particularly prone to breaking in fusion updates.. has it ever been working or were you only just implementing this feature now? can you re-create the problem in a new file? if you can, I'd submit it to the bug box.
how big is the frame for the sub app? it could be some kind of virtual width thing.. are there any screen positioning events in your subapp frame? (eg. start of frame center x)
Thanks for your help!
It has never been working, as I just implemented the pause feature.
I managed to recreate the issue, so I will submit it to the bugbox.
The frame size of the sub app is the excact same size as the pause menu, 352*128.
I have uploaded the mfa in case anyone wants to take a look