Linter dropdown not functioning on some OS X platforms

[sirlensalot]

Using linter 3.4.0, as a package dev (language-pact) I'm able to use the dropdowns in the linter editor UI. However some of my users are unable to; the caret doesn't even animate. Here's what we should see:

Instead (on my user's plaf) the dropdown doesn't even respond.

linter-issue.mp4

Here's the linter debug from the user (on OSX Catalina 10.15.7):

Linter Debug Info

Platform: darwin
Atom Version: 1.58.0
Linter Version: 3.4.0
Opened file is ignored: No
Matching Linter Providers: 
  - Pact
Disabled Linter Providers: 
Standard Linter Providers: 
  - Pact
Indie Linter Providers: 
UI Providers: 
  - Linter
Ignore Glob: **/*.min.{js,css}
VCS Ignored Paths are excluded: true
Current File Scopes: 
  - *
  - source.pact
  - meta.expression.pact
  - meta.definition.global.pact
  - meta.list.pact
  - meta.object.pact

Here's my (working) debug (looks identical, I'm on OS X Mojave 10.14.6):

Platform: darwin
Atom Version: 1.58.0
Linter Version: 3.4.0
Opened file is ignored: No
Matching Linter Providers: 
  - Pact
Disabled Linter Providers: 
Standard Linter Providers: 
  - Pact
Indie Linter Providers: 
UI Providers: 
  - Linter
Ignore Glob: **/*.min.{js,css}
VCS Ignored Paths are excluded: true
Current File Scopes: 
  - *
  - source.pact
  - meta.expression.pact
  - meta.definition.global.pact
  - meta.list.pact
  - entity.name.function.pact