The search on my wife's profile went fine.
Then I tried my son-in-law:
parents 25 / 2 25 / 2
grand parents 46 / 4 71 / 6
great grandparents 103 / 8 174 / 14
2nd great grandparents 209 / 16 383 / 30
... definitely some odd numbers!
I have found that after changing from the default person (e.g.: yourself) the first time, things are fine. However, changing to another (3rd) person does not behave properly. If I then click the HistoryLink icon, taking me back to the 'home' screen, and click the "Get Started!" button -- which reverts the default person to yourself -- then changing to the desired other profile ... then things work o.k.
In other words, changing the "root person" does not appear to 'clean up' properly after the first change (from the default to Person "A" works fine; changing to "B" does not work unless on 'reverts-to-default' first by going back to http://historylink.herokuapp.com