Multi-site Issue – Users from one subdomain can log into another


I don’t know whether this is a pro-site issue or a general multi-site one

I am creating a multi-site network for business clients where only users from each business can access their respective subdoamins.

So what’s happening is, in my multi-site network, a user from one subdomain can log into another and are given subscriber access.

For example

userA from subdomain “” can log into “”

How is this possible?

I thought only users who are registered to a particular subdoamin could access it.

Relevant info:

* Using WP 4

* Plugins used: Pro-sites and “Restict Site Access”

I thought the plugin “Restrict Site Access” maybe causing this so I deactivated it but that made no affect

As you can see my objective is to ensure privacy to each business within my multi-site network

This is an urgent matter

What do I do?

Thanks in advance