Contacts are syncing from everyone's devices

Our business has recently been having a problem with OwnCloud syncing everyone’s contacts, from everyone’s phone onto all devices. It’s all apple Iphones. I’ve never had a problem like this before and I can’t wrap my head around it. It’s syncing the contacts that are in ownCloud, but also seems to be pulling every contact from everyone’s device and sharing them, without them even being in the ownCloudContacts. For example we have about 115 contacts stored in own cloud, but have 212 contacts that are populating

Has anyone ever had this happen before? Is there any advice on fixing this issue?