Might it be that you commit the object twice in your microflow? I think you refer to the fix in 6.10.6:
And later on a simulair issue was fixed again in 7.2(third bullet):
If the same situation applies to you, you could create a ticket for it again.
Else a bit more information on your microflow setup and ideas you already tried would be great.
I while a ago I have submitted a similar bug to Mendix in the Mendix Email module which is not solved yet. I hope they will fix this soon.
I found where is the problem. The problem is with event handler ('Before Commit') which is called within action 'Commit' (Because action 'With events' is 'Yes'). When I put 'With events' to 'No' and call microflow (which is event handler) before action 'Commit' everything works fine. In other words when I simulate action 'Before Commit' with calling event handler microflow directly in my current microflow (before I committed the object) everything is fine.