Laying parquet - Expansion joint in screed of varying height

Hello you hardworking craftsmen,

I spontaneously helped a friend today to continue laying the parquet.
Now there is the following problem at the expansion joint of the screed. It is at different heights, difference approx. 1mm.
Unfortunately, it was neglected to correct this in advance. So a spontaneous solution is needed! So once again a challenge.
Spontaneously, I thought of an expansion joint with cork, but only a small strip of parquet would remain in between. Or to simply start the insulation foil later on the higher side, since it is only a thin moisture barrier foil, so that it somewhat evens out?
Does anyone have a suggestion or idea for a good solution? ?

Thanks already and wishing everyone a relaxing Sunday evening

Sorry...it's a 3mm difference instead of 1mm...was late yesterday.

Help me out briefly, just so I understand: the height difference between the two screeds is therefore 3 mm, right?

Then from my point of view there are two possibilities:

- ignore and continue laying
- insert an expansion joint at that point.

For a decision, I am missing information – is that the transition into another room or the hallway? Why is the joint in the screed exactly at that spot? Questions upon questions.

Help me out quickly, just so I understand: the height difference between the two screeds is 3 mm, right?

- yes, that’s how it looks.

ignore and continue laying

- then it will unfortunately wobble or whatever you want to call it. The lower board is basically hanging in the air

insert an interruption with an expansion joint at that point.

- how does it behave if the leftover piece of parquet is only 2. cm before the expansion joint? I think it would have to be glued for durability

But I lack information for a decision – is that the transition to another room or the hallway? Why is the joint in the screed exactly at that point? Questions upon questions.

- the questions are actually totally unimportant for the decision of how to proceed because they don’t change the problem.
- no transition. An expansion joint was installed in the attic, don’t ask me why. Maybe because otherwise the area would be too large?

Oh damn - so it's right in the middle of the room? Good grief.

How many meters have already been laid? Can you still push it? If a board lies right on the joint in the middle, I wouldn't worry about it. But the installer really screwed up there.

Honestly, at least 50cm out from the edge and then fill the slope.