Incorrect behavior in collapsed mode

1. Open "_common_data/scenarios/msa/ma.aln".
2. Click the "Enable collapsing" on the toolbar.
3. Open any group and try to edit any sequence:
3.1 Insert gap by pressing SPACE.
Expected state: gap was inserted in every sequence of this group. This is normal behavior.
3.2 Select some region of the grouped sequences in the Sequence area and drag this selection to the right.
Expected state: all sequences in the group are changed simultaneously.
Current state: selected sequences leave their group and create new group (or join another group).