All German prepaid providers charge the maximum for incoming calls in the EU that is allowed under the EU roaming regulation, which is € 0.10/min.
The only option to circumvent roaming charges when receiving calls abroad would be solomo, who include a free VoIP account (standard SIP) in their prepaid tariffs through which you can receive calls free of charge worldwide. But once you start using VoIP you should better grab a German landline number from sipgate.de which would also be free for you but cheaper for the caller than calling a mobile number.
Until recently Minutel, another prepaid provider which was taken over by Ring, offered free call diversions to landlines in most European countries, which was an alternative to being charged roaming fees for answering incoming calls, but it seems like they do not offer these free diversions anymore.
Actually
Yesss! is an Austrian MVNO.