Make list part expand fully when in a group with a field?

I have a list part in a separate group on a page.

I need to add another field in the same group. When I add, it looks like this:



I need the list part to fully expand, not be half and half like this.

I tried adding in subgroups to the field, to the list part and to both at once but no matter what I do they are divided half and half.

Any idea how to fix this?