Hi,
it is not possible to make a fetch request to Reddit or other websites which are on the Tracking Protection list in Firefox, if Tracking Protection is enabled in Firefox.
See https://github.com/cadeyrn/bookmarks-organizer/issues/26 and https://bugzilla.mozilla.org/show_bug.cgi?id=1308640 for details.
It seems to be possible if I request a host permission for Reddit but this can’t be a solution for my add-on, I can’t add thousands of different host permissions to allow all domains on the TP list.
So what can I do to check if these bookmarks are broken?