Sling TV credentials not working at all ("no login form found")

New cord cutter trying to use locast for local channels plus sling TV (despite limited TVE support). I'm only on a 3 day trial of sling now but I was able to, for example, use my credentials from sling to watch ESPN (via https://www.espn.com/watch) on the same laptop I use to manage channels.

Of note, the actual channels server and DVR are both being run from an nvidia shield pro. However, when I try to add sling TV as a TVE provider for channels, ALL I get is a single message at the top "no login form found".

I then tried YTTV (before realizing it was not compatible with the shield)...interestingly I get the exact same message.

Edit: I should mention that locast is working perfectly! Finally, sorry if naive but when I go to add source, it does say TVE is beta - I don't know if this is always the case or if I have a beta version...

Please go to Help -> Submit Diagnostic Logs from the web interface of the DVR and let us know when it's been submitted so we can have a better idea of what was going on.

Thank you so much. Just did as 41f6be28-39ce-46bd-964f-f0719a4952a8

BTW, in process of reinstalling the whole home client on both my shield and shield pro so that I assume is everything at the bottom of the log.