Ok, the node talbimman suggested (and Yna_Db properly named) worked.I had to add String.Contains and the primary list again, and then it worked. I’m still frustrated by the fact that my knowledge is so low, that I have no idea why something works or not! The working graph is the lower one.
Now maybe someone knoww what is happening in the upper graph. When I try to filter two lists using list.containsItem Which i hoped would filter out the missing types), or List.FirstIndexOf Dynamo, picks two random elements that are on both lists… Funny thing is, that when I deleted two different wall types, Dynamo then picked two other wall types (from different parts of the list), that also were present on both lists! List.FirstIndexOf used to work ok, but it seemed to have a problem once I added the delete node.