I can't seem to select a group and add a new item (label, button, control, etc.) in to it. I currently have to ungroup all the items and then re-group the items with the new item selected as well.
This is indeed a serious need.
Please, implement it. I hope it's not too hard to do.It will make creating PowerApps much less awkward to maintain.
The new enhanced Group control significantly improves the ability to add controls into an existing Group. This is starting as an experimental feature since we are replacing the existing Group concept.
You can read more about it in the blog post https://powerapps.microsoft.com/en-us/blog/enhanced-group-experimental-control-with-layout-control-a....