Hello guys,
Im kinda new to Houdini and did a tutorial about a building generator, which I pretty much understood everything. But now I have the problem that in my final merge node I get a warning that there is a mismatch of attributes which results in killing some of my UVs.

My question is now how to debug this? Where do I start and what do I look after? I know that the merge says what attributes are affected but I do not really know how to fix it.

I attach the hip file if you want to take a look at.

Thank you guys.