AA checkboxes visually broken on older versions of Chrome and Opera

Environment

OS version: (not OS specific
Browser version: Chrome versions 77-84, Opera versions 64-69
Extension version: current next branch (builds from this job can be used to reproduce the issue: https://gitlab.com/adblockinc/ext/adblockplus/adblockplusui/-/jobs/2687045434)
Last working version: 3.14.1

Steps to reproduce

Open settings page

Observed behavior

Struggling to descibe what I'm seeing, so I'm pasting screenshots below 😆 (Show acceptable ads and Only allow ads without third-party tracking checkboxes look like they have the 'default' checkbox inside them.)

Expected behavior

Further information

This issue is only present on older Chrome & Opera versions
The issue is only visual, functionality is not affected (selecting and deselecting checkboxes installs correct filterlists)
Introduced with https://gitlab.com/adblockinc/ext/adblockplus/adblockplusui/-/issues/581

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