@tommys
Replying to myself since I finally have solved the problem! Netatmo is now loading fine on the latest versions of MM and MMM-Netatmo.
The problem was actually caused by two independent problems: the module reordering algorithm and the sync-fetch library.
The workaround I did to solve the first problem was simply to not set the moduleOrder config property, easy as that.
The second workaround was a bit more involved, I completely removed the usage of the sync-fetch library in netatmo.js in favor of the default async version . That is, simply remove the line: const fetch = require(‘sync-fetch’), make the authenticate, loadData and socketNotificationReceived functions async, handle the promise object returned by fetch appropriately as well as the call to json().