Many thanks @Evgeni_Popov! We greatly appreciate how quickly the BabylonJS team gets fixes published.
Fwiw, it makes complete sense to me that one wouldn’t use the adaptWidthToChildren / adaptHeightToChildren properties on a StackPanel if the StackPanel already adapts size to its children.
I’m upgrading my project to version 4.2.0-beta.1 right now to confirm the fixes (I didn’t see a way to choose this specific version in the playground). I’ll let you know if any issues persist.
BTW @Evgeni_Popov, I think this fix you made may also fix the bug/question I posted last week regarding ScrollViewer.