I’ve found a solution here but it sounds like you tried that exactly.
One work-around that I could see is downloading the csv of all zip codes in Germany here (box on the right) - and then copy and paste the whole list into the filters field. This usually takes a moment for a long list (potentially ~29k zip codes) but usually works. Just give your internet browser a moment to cope.
If none of these work, this might be a bug worth flagging with support.
You can have multiple filters and can use * to define all fields.
For example have I filtered here for postcodes containing 10 and 22 and get the corresponding results. Is that what you meant or where you after something else?
Not sure what you mean by “options are blocked with a red sign”. Can you maybe include a screenshot that shows what you are doing, where in the tool and what you are seeing.
How can I create a list or filter to display companies by postcode (PLZ), such as those starting with “8”, when options are blocked with a red sign? Just click here