The anomaly here could be this.

Some guides use 10% either way for a winning distance
While others don't.

So Kirvic won its only race in a maiden at Naracoorte in,
Sept last year over 1430.

Add 10% like some guides 1430+143= 1573.

This would show in some guides as having won in this,
Particular distance range today 1550 while others who don't use the 10%.
Rule, only the 1400 distance rule won't show it.

I have never visited the Unitab site so can't comment on their procedure,
Or where they obtain the data from.

But as M.G. has based his bets on this site that's the best way to do it.

This is only my suggestion as to why some will, some won't,
have this stat.

Cheers.
Gary.