Heads up, Creators: On Dec 13-14 you may see a noticeable decrease in your sub count as we remove spam subscriptions. If spam is removed, you'll see a YouTube Studio alert: https://goo.gl/qGDBvX This should help give you confidence that the subs you do have are real fans!
Do you see this happening across devices? Does it show subscribed from the channel page and Subscriptions Manager? Also, try signing out and signing into you account to see if that makes a difference. Keep us posted.