So I'm entirely unable to authenticate my last.fm account in the Spotify mobile app, and I haven't been able to *ever*

last.fm scrobbling works fine on the website, on all my pc's using the browser extension, etc.

I've tried an entire re-install of the app, I've entered my information numerous times (it's being entered properly, no trailing space on either the user or p/w). I've tried using my email instead of username. I've cleared all data associated with the application. I've changed my last.fm login information. All of this to no avail. The app *immediately* tells my that it failed to log in.

Spotify Version: 8.4.1.846 armV7 (current, this issue has persisted through many versions)

Android Version: 7.0

Phone: Motorola Z Force (Also have tried on wi-fi using an LG G3)

I'd be happy to provide any other information that may help to solve this issue, most of my spotify listening is mobile, and I'd *really* like to have that info scrobbled...