For the record, that NET ranking is from WarrenNolan.com (not the NCAA), and is one of the better websites that estimate NET rankings, and which will usually be what the NCAA will show when they start posting NET rankings sometime in December.
I'm not an expert, but from what I've read, there can be differences maybe because the NCAA's NET formula is quite a bit more complex (see below) and includes a number of analytics, scoring margin, etc., and there might be differences in the way the NCAA comes up with those compared to what bloggers use.
There have also been differences in what is considered a home game vs. road game vs. a neutral court game, which can affect the NET significantly.
Example: last year Bradley played Arkansas at a neutral site in Little Rock, not at Arkansas' home court in Fayetteville. But if you look at
WarrenNolan.com schedule page for Bradley from 2022-23, they assign that game as a true road game ("AT Arkansas"). Maybe the NCAA did that, too, since it was a big home advantage for them, but I don't know if they reveal those things.