Speaker flashes when first used on Firefox

[loganbraywork]

Test device

Windows 10 Laptop

Operating System

Windows 10 v.1903

Browser

Firefox 81.0.2 (64-bit)

Problem description

For https://github.com/phetsims/QA/issues/511

On the Sound Screen, when the Speaker is activated for the first time it flashes white. This seems to only occur in Firefox, and only on the first use of the Speaker in the sim.

Steps to reproduce

1. Refresh the page if the Speaker had already been used
2. Interact with the Speaker
3. Refresh page and repeat to view again

Visuals

Troubleshooting information: !!!!! DO NOT EDIT !!!!! Name: ‪Waves Intro‬ URL: https://phet-dev.colorado.edu/html/waves-intro/1.1.0-dev.24/phet/waves-intro_all_phet.html Version: 1.1.0-dev.24 2020-10-13 16:44:23 UTC Features missing: touch Flags: pixelRatioScaling User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0 Language: en-US Window: 1536x750 Pixel Ratio: 1.25/1 WebGL: WebGL 1.0 GLSL: WebGL GLSL ES 1.0 Vendor: Mozilla (Mozilla) Vertex: attribs: 16 varying: 30 uniform: 4096 Texture: size: 16384 imageUnits: 16 (vertex: 16, combined: 32) Max viewport: 32767x32767 OES_texture_float: true Dependencies JSON: {}

[samreid]

I was not able to reproduce this problem on macOS 10.15.7 running Firefox 82.0.2 (64-bit) and https://phet-dev.colorado.edu/html/waves-intro/1.1.0-dev.24/phet/waves-intro_all_phet.html

[samreid]

Testing on Windows 10 Home 19041.572 running Firefox 82.0.1 I see a delayed appearance, then rapid flickering on first use. After updating to 82.0.2, I see rapid flickering on first use.

[samreid]

@jonathanolson recommended testing with renderer: 'canvas' and that seems to be working well and without side-effects. I published a dev version here which can be used for testing: https://phet-dev.colorado.edu/html/waves-intro/1.1.0-dev.25/phet/waves-intro_en_phet.html

@loganbraywork can you please test in dev.25? Close if all is well.

[loganbraywork]

Seems fixed, was not able to reproduce in https://phet-dev.colorado.edu/html/waves-intro/1.1.0-dev.25/phet/waves-intro_en_phet.html