I had the same issue yesterday after upgrading my MSI Z690 Carbon to the 7D30V18 BIOS released Sept-13th. MSI notes the update addresses CPU Microcode and PCIe storage compatibility. Both of which I had been having issues with.
I've had random reboots after updating to the v17 BIOS that supposedly addressed memory compatibility issues. However, issues arose from the CPU - discerned from event log errors with e-core parking, and an PCIe storage issue with an ADATA NVME drive, which was viewable, but unable to be interacted with by me or the OS.
I have four NVME drives and the Samsung and WD NVME drives were fine. I've been running the Insider Preview of W11 2022H2 with very few issues. I opted back into the release candidate preview before updating the BIOS and had no issue with the license. I have no idea at this point on how to proceed other than to inform both Microsoft and MSI.
I think the license "issue" arises from the BIOS update erasing the unique ID numbers from the bios as software like AIDA or the MSI Center no longer shows the unique ID string or serial number. Another symptom appears from my Microsoft account, as managing the devices now shows my current desktop twice, but I am afraid to delete one and accidently make my digital key unretrievable. In fairness to Microsoft, it seems like a major MSI error. Which is still not fair, and I am trying to figure how to reactivate W11 as well. I've been presented with the same unsuccessful reactivation options as you, and nothing from internet forums have yet worked.
I don't know if you/we can roll back the bios to an older version to an older one to see if it reactivates or at least it recognized until MSI resolves their current BIOS issues. I have not tried just yet, as the last version had major issues. Right now I just have a water mark but finally have stability. I'm not sure how Microsoft assigns or associates the key. I assume with the UUID in the bios. It might be the last resort though.