Just came across this working in Arrangement.
3 audio tracks grouped. This is the last group track from the bottom where 2 audio tracks are left underneath it. The Group can be opened, but there is no way to resize. As you can see in the pic you can only see the top half. I made the tint.
8.4 Windows 32bit
Group Track Bug in Arrangement
Re: Group Track Bug in Arrangement
I have experience this same bug.