Wordpress SOS Plugin Stopped Working

[Piano Lesson With Warren]

Hey All, 
Looking for so help in troubleshooting why the Wordpress SSO plugin stopped working. I use this plugin to bridge a single sign-in between Wordpress and IPboard forum.  I set this up in January, and everything was working great, then I believe on 3/31/20 it stopped syncing new users - new users can't seem to access the forum when they log into Wordpress.

I figured it stopped working on 3/31/20 as that is when is last synced a user, and it hasn't synced users anymore since then, and I've had over 100 new accounts created since. 
I can't seem to find any troubleshooting steps on the plugin, and I've reached out to the developer here in the community, and haven't heard back 
I'd greatly appreciate any help. 
Thanks,