already have, matching the domain of the webpage
but i doubt that that would be the problem, as then the test mal() php would not have worked
yet i found the problem

apparently there is something wrong with the regex to check the telefone nr
i removed the check and it works
strange however is, that not even the error message showed uppon entering a wrong tel nr
and that the check was already in place when the original test worked - maybe the host updated php which then didnt like the regex anymore?
thank you guys a lot for your help anyhow