Neos Forms Translations of Validation Results are only in English on the Mac Safari

Hello Everyone,

I just found some strange behaviour on my Mac and not sure how to fix it.

First I found this on the plugin cron.formbuilder and verified that is a general problem with Neos.

I’m working with a Mac on Safari (latest Version). My User has the German Language as devault selected.
I try to add a new User and the validation of these form works fine - but all the validation-messages are in english and below the input field.

When I try this with my firefox on the mac it works fine - I get this nice little overlay messages and they are translated.

Has anyone an idea how to fix it on safari?

Thanks in advance