When I signed into my Microsoft account via the Bungie.net/redeem website to enter a code, A random gamertag I had never heard of popped up asking if it was me. I have only ever had one account and it is all connected properly but this was showing a different account. Was someone trying to get access to my Bungie account or is this something else? Anyone else experienced this?
I don't know but it sounds fishy. I would contact Microsoft support, change your Microsoft password, and enabled 2fa on your Microsoft account. Just to be safe.