Hi there,
It seems that there are issues on our end. I have logged this issues internally and those fixes will be included on our next release version.
By the way, currently, there are no setting to enable or disabled them currently, i just applied some fixes on attached files, where it will always display user's last seen. You can try to applied attached files at this path .../components/com_easysocial/themes/wireframe/helpers/cover/user.php or do template override on this path template/html/com_easysocial/helpers/cover/user.php
Please give it a try and see how it goes.