On my Facebook page it tells me I have had 11 shares. There is a link to view all shares. I click on this link and I only see 2 shares. Why am I seeing only 2 out of 11 shares?
You can only view the shares that you have access to - that is, shares by your friends, or shares which are public.
I believe in testing, page admins could see all of the shares of their content, but this has been locked down.