Greyed out arrow button not fully rendered

[ghost]

Test Device

Tycho

Operating System

iOS 9.3.5

Browser

Safari 9.0

Problem Description

Found during phetsims/qa#214. See title and screenshots. Behavior not consistent. Sometimes happens with half of an arrow, sometimes the whole arrow, sometimes two arrows, sometimes one arrow.

I'm wondering if this is an example of #654. If so, please feel free to close this issue.

If not, I can open an issue in the CL repo.

Steps to Reproduce

1. Atomic Scale screen.
2. Set both Charge 1 and Charge 2 to one extreme (+10 e or -10 e).
3. Move one of the molecule figures around.

Visuals

[jessegreenberg]

I have an iOS with 9.3.5, I was only able to reproduce consistently when tablet is in portrait orientation, even then it only happens sometimes when moving the . This looks a lot like #654, and if I can't reproduce with rootRenderer="canvas" Ill move to that issue and close this one.

[jessegreenberg]

AFter trying for several minutes, I am not seeing this happen with canvas, so I assume this is the same as #654. Ill close this issue and make note of this one there. @jonathanolson please feel free to reopen if that is not correct.

[jessegreenberg]

Also pinging @mbarlow12 since this came from a sim that he is working on.