Yeah I might have to give the Reset-Scroll-Position-on-Page-Load method a go too. It appears that the issue only happens on some of the Powerapp forms I have.
@_Corey_ - I actually don't know how to open a customised SharePoint List Form in PowerApp Studio. My changes are always made by opening the list in SharePoint, pressing "PowerApps" and then "Customize".
However, it now looks like the problem is fixed when customizing and publishing through the online Powerapp Editor, as the main form I usually experience the issue on is working fine now.
@DWahry I'm glad to hear all is well! And, yes, opening the form via PowerApps -> Customize opens it in PowerApps Web Studio, which is what I had meant by Studio.