It sounds like you are running into a known bugs we have on file for iOS devices where:
- Interactions will jump to (0,0) if the design is scrolled past the edge of the device width or height when the HTML sidebar is opened or minimized
- ScrollTo and OnWindowScroll events to not register when the HTML sidebar is opened or minimized
I'll be adding this post to the reports we have on file, but for the meantime, it'll help to view and interact with your prototypes on iOS devices with the HTML sidebar completely closed. You can close the HTML sidebar by clicking on the "Close" button on the bottom-left corner of the sidebar dialog. Or, opening the prototype directly through the Axure Share mobile app will automatically open your prototype with the HTML sidebar completely closed.
Hopefully this helps, but please let me know if you're still having trouble. Ty!