Lost minecraft license after migrating my account

I migrated my account back in June, got a mail saying it was successful and didn't think more of it. Today after not playing MC since 2019 I felt like playing again after seeing that Tekkit was back. However when I log into my Microsoft account, my only Microsoft account, all I get is the option to buy the game again, even though I've owned the game since early Alpha.

I've tried contacting support, but the reply I got said they don't help with migration related issues anymore.

Anyone have had the same issue as me? Is there any hope to resolve it or am I SOL?