2013 E350 sport w212 transmission

  mercedes/e-class/2010-2016

I have the 722.9. Shifting is normal, almost seamless until shifting from 3rd to 4th gear. There is a jerk, almost like hitting a bump in the road. Ive tried accelerating slowly and semi aggressively and the outcome is the same. There is no noise such as grinding, whining, rattling etc...just a bump.

What are the possible causes?

The car has 41200miles and it seems I am the third owner, maybe the second.

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