Auctioneer Undercutting Incorrectly

I'm playing on Lordaeron, and this is what I noticed Aucitoneer's undercut feature doing to SOME items, like Bruiseweed:

my undercut settings:
https://imgur.com/a/oJC7vjR

the lowest price I found for a stack of Bruiseweed is 5 gold for a buyout and 4g 20s as a bid start:
https://imgur.com/a/YsnKe3b

and here's what my undercut price ends up with when I want to add it (4g 79s 83c), which is not the undercut I set up in my settings (1s 1c):
https://imgur.com/a/lLFjpK5

can anyone tell me what am I doing wrong?

Are you sure there aren't cheaper auctions in first 2 pages? You can check "Show stacks as price per unit" at the bottom to see price per item instead of price per stack, in case an auction with smaller stack size has cheaper price per unit. And order by "Pct" column to see cheapest items at the top. Or in Post tab reverse the sort order by clicking on "Buy/ea" column. Then you would see cheapest auction at the top. Otherwise nothing in your screenshots shows that what's on page 3 is actually the cheapest auction.