USER NOT ACTIVATED

Yes, this is in fact a bug in the current version of the plugin. It stems from a change to the wpmem_activate_user() function, which is not an official part of the user API. That function has an optional argument to toggle whether the notification is sent or not. The activation from the user profile screen wasn’t properly defining that argument.

I’ll be pushing out an update to fix this, but in the meantime, you can replace the /includes/class-wp-members-user-profile.php with the version here:
https://gist.github.com/rocketgeek/adc83ccdd741bc06852ee1da0f28a406