Hierarchy grid - Inner grid column width larger than setting

Hello,

I have a hierarchy grid set up. The outer grid has a dozen or so columns while the inner grid only has 3 columns. I have specified specific widths for all the columns however the columns in the inner grid do not respect the width values set and expand to the full width of the outer grid.

So instead of looking like this:

..|.A.....|.B.....|.C.....|.D.....|.E.....|.F.....|.G.....|.H.....|.I.....|.J.....|.K.....|.L..
..>....|.1.....|.2.....|.3...

It looks like this:

..|.A.....|.B.....|.C.....|.D.....|.E.....|.F.....|.G.....|.H.....|.I.....|.J.....|.K.....|.L..
..>....|.1................................|.2........................|.3..............................

I don't really care if the inner grid itself is streatched to the full width of the outer grid but the columns need to respect the width I set so it's easily readable.