Hi Jeremie, Yes, and the WAB 2.4 one is 2.1.2 now. I narrowed it down:
1.3.3 works perfect in all browsers.
2.1.2 works in all browsers, except Chrome. It does not download in Chrome.
2.1.2 works fine in IE 11, Firefox and Edge. Just Chrome that won't download in 2.1.2. Chrome Version 60.0.3112.90 (Official Build) (64-bit)
With 2.1.2 now using Esri jimu.js download utility, maybe Esri needs to update jimu.js to work in Chrome? Perhaps Chrome does something 'different' than the others. But now that Chrome is basically the new default for the internet... I hope it can work.
Jeremie, Question - you said you couldn't replicate it? So, in your Chrome, 2.1.2 downloads? What Chrome vers are you running?