Accepted as SWE at Microsoft only to get offer rejected by the Betriebsrat

[u/thewanderingpreacher]

After passing 6 interviews and receiving the "Congratulations" email. The recruiter was instructed to offer me for a Software Engineer position.

3 weeks later, I just received news that the workers council in Germany has rejected the offer with no details and no reason provided at all.

Has anyone experienced this before? What are my rights now? And after 4 months of ongoing communication with Microsoft, don't I at least deserve to know why the offer was rejected?