I have just seen this thread; I'll try to help where I can, but those things are complex and there are many things to unpack here... Windows does not (out of the blue) activate it on its own, there is a recovery key (which is different from the BitLocker password) during activation for safeguarding... If it were actually activated, and you have a Microsoft account linked to your user in that machine perhaps they key is saved there? See here if that were the case: https://account.microsoft