Help! Activation Lock Issues with My MacBook Air

I'm facing a really annoying activation lock problem on my MacBook Air M1, which I bought new back in 2021. Here's the situation: I originally set up the laptop with my Apple ID, but I've changed the associated email address twice over the years. Luckily, I kept my password history stored in 1Password, so I haven't lost any credentials. Now that I'm preparing to sell the Mac, I ran into a major issue during the reset. The OS is asking for the password linked to my old Apple ID email from 2021, which means it's not recognizing my current email. I tried both my old and current passwords, but neither worked.

Here's what I've done so far: I logged into iCloud and removed the MacBook from my account, which led to it getting wiped. However, after rebooting, it remains Activation Locked and demands the original Apple ID credentials. I also contacted Apple Support and submitted an official request for Activation Lock removal with proof of purchase, but they closed my ticket without helping me. I'm the original owner with the invoice, and I live in Germany, which I thought might be relevant. My Mac is essentially bricked, and it seems impossible to unlock it even with the correct proof of ownership. Has anyone dealt with this before? Any tips on overcoming a denied unlock request or refreshing the activation status? Thanks and happy holidays!