Here is the general info on such a 'specific' missfire.
When in those driving conditions the EGR is opened by the computer to let some exhaust gas back into the intake.
The ignition timing is advanced and fuel is cut back.
This results in a very lean mixture in the 20 to 1 range.
A lean mix requires much more spark voltage to fire the plugs .
If one coil has low output "under those driving conditions" a miissfire/stumble results.
As soon as the driving condition changes that cause the EGR to close, the missfire goes away.
This cancels a pending code for that cylinder because the condition has cleared. (Not a hard fault)
Bottom line is a coil is ususally the cause with shorted internal turns in it's winding.
It may be posible the EGR opening is more that it should be or letting to much exhaust gas return to the intake.
It's a toughy to get hold of but now you know the basis behind the cause.
Good luck.