@ArtificialAI Hello! I hope I can give you a hint although I don’t use the module ^^
I just noticed that you use different units for the same conversion and it looks a little weird for me. Maybe you can mention in what unit the value data.capacity.disks.free can be read out?

In the example entry in your config.js you have TB:

formatter: "(data) => (data.capacity.disks.free / 1024 / 1024).toFixed(2) + ' TB'",

In your formatter examples you have GB:

(d) => (d.capacity.disks.free / 1024 / 1024).toFixed(1) + ' GB'

Best regards,
sletrabf