The poll in NC with Biden leading 48/44 is nearly identical to the last CBS/YouGov poll done in NC in 2016 on Oct 26-28 which had Clinton up 48-45, what is different is Trump was up 22% with whites in that poll vs 17% now, but he is only doing 1% worse overall, I would guess due to him not not doing as badly with non-whites.
He has 5% among blacks in the NC poll
Blacks are not the only non-whites in NC, 10% of NC's electorate is not white or black, as I've said he is doing 5% worse with whites in this poll compared to the Oct 26-28 YouGov poll but only 1% worse overall so he must be doing better with non-whites.