I think the ‘Sons of God’ were probably divine beings, due to the following verses:
Now there was a day when the sons of God came to present themselves before the LORD, and Satan also came among them.
If Satan was among the Sons of God, then they too must have been divine beings.
For who in the skies can be compared to the LORD? Who among the Sons of God (Bene Elim) is like the LORD,
These are clearly heavenly beings here.
I say, “You are gods, children of the Most High (Bene Elyon), all of you; nevertheless, you shall die like mortals, and fall like any prince.”
It makes no sense to declare that a normal human will ‘die like men’. The phrase ‘Bene Elyon’ is also giving to divine council members in Ugarit.
Perhaps most importantly is Deuteronomy 32:8:
When the Most High gave to the nations their inheritance, when he divided mankind, he fixed the borders of the peoples according to the number of the sons of God.
The context here is that of divine allotment among the nations, as in the next verse it is declared that Israel is YHWH’s portion. Context then suggests that these Sons of God were divine.
This verse refers back to the Tower of Babel, where the language used is very similar to that used in Genesis 6, which can hardly be a coincidence, since both have a link to the Sons of God. I think this is probably the best evidence for Divine Nephilim.
Now Israelites are called ‘sons of the living God’ in Hosea 1:10. But this is only one verse, compared to many more verses where the term clearly refers to divine beings.