You've an awful lot of repetition in there, which makes it hard to read the macro. More importantly -- things like repeating your "Linie 1" dialog four times will make it more difficult for you to maintain.
One way round this is to consider that there will always be a "Linie 1"; if the number picked is greater than 1 there will always be a "Linie 2"; etc. So (and assuming you want to keep your first prompt the same) you could start with:
...and do similar at the end to "build" your var_dienstAmo variable before using a single action to paste it.
Using Global variables could also cause problems -- if you select "1 Linie" in the first prompt all your "2", "3", and "4 Linien"-set variables will still values from previous runs of the macro. Perhaps one of those variables has some conflicting data, which is why there isn't a problem in @ccstone's tests?