Mod menu changed recently and the icon here is now invalid:
[21:50:43] [main/WARN]: Warning! Mod chunky-fabric has a broken icon, loading default icon

How are you accessing this mod menu? I'm familiar with the one on Forge but I have not seen it in Fabric.

I was made aware that this is itself a mod. Added support in d645eeb, you can download the latest version here.