UI Rendering Glitches After Spawning Multiple Entities

[indiv0]

bevy_rapier version: https://github.com/indiv0/bevy_rapier/tree/5d19dc991cc3f18d9012524d08ff30ade915a2ae
bevy_webgl2 version: https://github.com/indiv0/bevy_webgl2/tree/a53c9ca296a46019d833da9be6f69f099ac63159
bevy version: https://github.com/bevyengine/bevy/tree/2e2423139e0cd8efda3aa0d474d3eb231dad566b
Example source: https://github.com/indiv0/colonize/tree/75ee66f710a4b9444a4b2119f27422e6fdeb3723
Example compilation args:

cargo build --target wasm32-unknown-unknown --no-default-features --features wasm
wasm-bindgen --out-dir target --target web target/wasm32-unknown-unknown/debug/colonize.wasm
wasm-opt --debuginfo -Oz target/colonize_bg.wasm -o target/colonize_bg_opt.wasm
sed -i 's/_bg\.wasm/_bg_opt\.wasm/g' target/colonize.js

Example demo: https://dev.colonize.rs/
rustc version: rustc 1.50.0-nightly (f0f68778f 2020-12-09)

Hello!

I have a game I'm working on. Currently you can spawn cubes in the game by pressing T.
This will attempt to spawn cubes in the air in some radius above the origin coordinate.

On some platforms (Firefox on Windows on my laptop) I've observed behaviour where if I spawn a lot of cubes at once
the UI begins to glitch out. It's not a framerate issue, but rather meshes start being drawn/not drawn at random.

You can see an example of the behaviour here:

I think this might be caused by me spawning rigid bodies/colliders within one another since my spawning algorithm doesn't prevent that, but what's weird is that it doesn't happen on any other device I've tested.