I enable WPMUDEV Dashboard support FYI so you can look for yourself too.
WP MULTISITE NETWORK Active In columns not showing subsites that are active for themes & plugins.
This explains inside the Network Admin area:
What are your thoughts of what I can try or what you can safely do to get that back. What would cause that? Is Active In part of the stock WPMU setup or a plugin (I actually can not remember myself at the moment).
That a bunch!