I think there is two miss-understandings here...
One, would first need understand where the rewards are comming from before starting to question the wallet or transactions seen on chain.
Second, no one can convert HIVE rewards (from hive posts, and assuming 0% beneficiary) automatically without the account receiving the rewards and then doing something with them.
(assumes your account has no delegated keys)
So, when you say your HBD, do what do you mean?
- The amount in the wallet? (if so, the answer is, only you can do stuff with it)
- The amount pending payout (and assuming no beneficiaries, then the total amount will be yours too).
- Any amount going to beneficiaries - Well, in this case, ANYthing can happen... but effectively anything that is going to beneficiaries is not yours anymore. Beneficiaries are only set during the first post/comment.