Welcome to our forum.
I just test team plugin with WP 5.0+ its seem working fine.
Can you please enable debug and log
you need to put the following code to your config.php file on root install
define( 'WP_DEBUG', true ); define( 'WP_DEBUG_LOG', true );
Please check the debug.log file and see if you found any issue related to our team plugin.
Let me know the update.