One subsite on my multisite network can view the statistics for all other subsites on my network.

One subsite on my multisite network can view the statistics for all other subsites on my network. All the other subsites are displaying the stats correctly - just this particular subsite. This subsite used to work correctly but now it doesn't so not sure what happened or how to fix it.

So to clarify each subsite should only be able to view the stats for their subsite. This is the ways its been woorking for a while with no problems. However, just recently one subsite can now view the stats for all other subsites (including its own).

So far I have tried:
Changing themes - still not working correctly
Disabling all plugins - still not working correctly

I am really struggling with this one - I appreciate any help/direction anyone can give.

Thank you in advance!