HookPad adding invisible rests to tabs

While working on a HookPad I’ve found that the tab will occasionally prevent me from editing the 5th bar of the first voice. After reloading the page I find that a rest has been inserted on this bar, but said rest was not inserted by myself and was effectively “invisible” prior to this.

http://www.hooktheory.com/hookpad/view/k7odLGp1rCQO

The link in question is the tab I was working on. The bug occurred while editing the first voice on the 5th bars of row 2 and 3. I was unable to replicate the bug on the following row so I’m not able to screenshot it at the moment.