CORS Issues when previewing a moderation list

[TheCleric]

When previewing a moderation list (even just the default one when creating a new one) the following error appears on both Chrome and Firefox (other browsers not tested):

The stack trace (from the copy stack trace button) itself doesn't look super helpful:

XMLHttpRequest error.
Error
    at Object.bqG (https://skyfeed.app/main.dart.js:7312:19)
    at an8.$1 (https://skyfeed.app/main.dart.js:119884:62)
    at afG.De (https://skyfeed.app/main.dart.js:52870:33)
    at b1x.$0 (https://skyfeed.app/main.dart.js:52252:11)
    at Object.Gy (https://skyfeed.app/main.dart.js:6066:40)
    at av.mi (https://skyfeed.app/main.dart.js:52173:3)
    at Object.bda (https://skyfeed.app/main.dart.js:6178:8)
    at aI8.$1 (https://skyfeed.app/main.dart.js:52419:9)
    at aZA.$1 (https://skyfeed.app/main.dart.js:56936:21)

However in the network tab it looks like a CORS issue: