Thanks for the query, it shows that forward_action = 0 which means it was not forwarded. I have confirmed through my testing this bug exists on my Prod, Test and Dev systems and affects multiple workflows ( I have not tested all and everything I tested fails).
I hate to think I am the only one with this problem.
Can you do me a favour and test your system. Create a Request with a task assigned to a single group, then have somebody else take action on the request and then you take action again. Then see if the work flow forwards to the assigned task to that group. In the history of the task I see the 2 activities of taking action on request as "Deffered Approval by" the action taker. Then instead of saying "Task Forward Internally to ...." All I see is "Approval Updated" then "Approval Actioned by ...". This does not affect multiple assignment for Stack holder or reference to a field on teh request screen.