Hi,
first of all I must tell you that we are not an A-kasse - we are a general guide about all the Danish A-kasser. So we can never help with any financial support - only guidance about membership and the rules.
However, when you work in Germany, you are covered by the social security/Unemployment Insurance Scheme in Germany.
So therefore you must contact the relevant authorities in Germany - about Unemployment benefits you must contact Bundesagentur für Arbeit. I have found a page on their website about kurzarbeitergeld, which I think can be relevant for you. There seem to be an option to get some supplementary benefits if you have "kurzarbeit". You can find the page here:
https://www.arbeitsagentur.de/finanzielle-hilfen/kurzarbeitergeld-arbeitnehmer
But you must find out if you have to meet certain requirements for getting the benefits in Germany.
Best regards,
Anders Weber, www.a-kasser.dk