The winning bid is $0.50 higher than the second highest bid. I believe that’s the increment for the $20 range. These two bidders were either manually making the last second bids or using bots that you can preset to make a bid with X seconds remaining. Both are allowed/not uncommon practices I believe.

Bid Amount Bid Time
p***c(1726feedback score: 1726) $23.39 13 Jun 2021 at 5:27:55pm PDT
7***2(3848feedback score: 3848) $22.89 13 Jun 2021 at 5:27:55pm PDT