Now the only question is whether I should have known that and it can be blamed on me or whether they laid the floor too early.
Difficult. As a homeowner-builder, you know that there is still residual moisture in the screed that needs to escape. As a tenant, rather not. But that doesn’t matter. You unknowingly "damaged" the floor. Try to have it covered by your insurance; otherwise, it will be settled through your deposit. You will have to pay for the repair, no matter what. Unless your landlord doesn’t care about something like that. We are moving out in 2 weeks as well and after 7 years have left some marks in the apartment. I assume everything will be settled through the deposit.