HI there Ross 🖐,
when you open a bunq account as German resident -> German bunq account, then the initial sub account created at account creation should have a German IBAN.
If that did not happen, you should contact bunq support to have it fixed.
🌈 https://together.bunq.com/d/1038-how-can-i-contact-bunq
I believe there are still issues for bunq account holder which were enabled before the German IBAN were available.
Alternatively, you should be able to add a new sub account and pick the German local one:
🌈 https://together.bunq.com/d/43452-german-ibans-hello-germany (in case you did not have the link to this doc).
Regards ☀️
GG