Crack in 60x60 living room tiles across multiple tiles. Experiences?

First, ask the builder or provider. Maybe it's just shoddy workmanship. Then it would rather be a case for the expert

1.) The builder will surely not admit that any construction work in his area of responsibility is "shoddy workmanship." 2.) Read my note: The warranty expired after 5 years. It's no use coordinating briefly with the construction manager from back then. 3.) Correct, this is a classic case for an expert. And such an expert, sworn for the floor trade, also answered you about 50 minutes ago! So, no questions remain open for anyone .....

Many thanks to everyone. Especially to for the very detailed response and expert assessment. I will have the specialist take care of it. PS: The tiler sold his business about 4 years ago and is taking care of his family. I believe the developers are also retired by now ;)