Broken tiles warranty? New apartment from the developer

Hello. I bought a newly built apartment from the developer. It was completed at the beginning of 2023. Now my tenant informed me that two tiles in the bathroom are broken. I wanted to assert my warranty claims... then this came: we are very sorry. But after consulting with the construction management, I must unfortunately inform you that these cracks in the tiles are not covered by the warranty. Due to the physical properties of the building materials, cracks can occur in components because of shrinking, creep, etc. A more detailed description can be found in your purchase contract under the section [Mängelrechte §4]. With this [§4] they can simply attribute any defects to physical causes. Is this legal??? Thanks and regards

Well, you signed a purchase agreement and probably didn't have it properly checked

What does it say under §4 in the contract?

What is stated under §4 in the contract?

The sales contract states:

The seller points out that
cracks in components, plasters, etc., which arise due to the building-physical properties of the materials (shrinkage, creep, etc.), do not constitute defects as long as they are within the permissible tolerances.

What would worry me much more than the tiles... how does the screed underneath look? Is it cracked as well? Because then that would definitely no longer be understood as settlement cracks. Screed is not allowed to crack and it does not settle.

Photos and a better description of the situation would be helpful. However, I am quite sure that the developer will not succeed with the argument.