I would think it's Avast's fault and not MS. This feature has been working for me and I just installed the paid version of Avast, and it was still working. Then I ran the various scans/performance enhancers that it came with and now MS Edge no longer auto populates log-in information or passwords, even though the settings are set to do so. That would have been too much of a coincidence that everything was working fine for a week after installing Avast until I ran those add-ons (PC Speedup, Disc Cleaner, etc.). A Google search to try and fix the issue led me here, but there doesn't seem to be any solutions available.