Too much data makes horizontal lines disappear

[RogerKratz]

I have some graphs that over time gets more and more data. At some time the horizontal lines suddenly disappeared so I guess there is some problem with too much data (?).

https://rogerkratz.github.io/BooliStat/

If showing less data using the slider, the horizontal lines pops back.

The problem occurs both in Chrome and IE.

[mirabilos]

Is this still pertinent? I don’t see any lines vanishing on the linked page…