System Information
Operating system: MacOS 10.15.6 Catalina
Graphics card: AMD Radeon Pro 5700 XT 16 GB

Blender Version
Broken: 2.83.4 2020-08-05
(example: 2.79b release)
(example: 2.80, edbf15d3c044, blender2.8, 2018-11-28, as found on the splash screen)
Worked: (optional)

Short description of error

When working in workbench, icons are missing in some add-ons like boxcutter and hardops. Both are the most recent versions 7.16.15 Catlin and 9 MercuryX respectively. When changing workbench, to EEVEE, the icons show up normally.

Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).
I normally work on workbench. I installed first HardOps following the instructions to unzip file directly inside the add-on folder of blender. Installed box cutter normally by using blenders add on installer in the preferences panel. I uninstalled and reinstalled both apps in different ways and I always got the same error. That is until I switched to EEVEE. Restarting the app again in workbench makes the icons disappear again.