The problem with treating the Bible as a factual account is nothing adds up in it. Saying Beelzebub is a “name of Satan” is really misleading and a result of later negotiation with the text. Just like the serpent in the garden of Eden wasn’t Satan until folks decided it was - there is no support for that in the text at all.
Satan is more like calling someone enemy - you can have lots of enemies without them all being the same entity.