Floor plan planning shortly before submitting the building application

You need a good expert, he will be able to tell you what the cause is ....

The cleaners dismantled the gutters so that the water fell directly onto the porch during heavy rain and penetrated from there into the guest bathroom. The stains in the basement were found to be solely from the cleaning work. So, construction will continue.

For you and your health, it would probably be better to only enter the house again after the key handover.

Such things lead to some people only buying used and never wanting to build!
Or should I rather say, these stories lead to that.

At least it's good that it was "only" operational errors and not construction defects.

The cleaners have dismantled the gutters.

Aren't you currently doing the interior plaster? Why then remove the gutters?