admins locked out when using correct password

I have 6-7 users on a multi-store system who all access the admin panel at the same time. problem is most of them keep getting logged out and told to wait 15 mins to try again... their passwords are not being entered incorrectly (browser stored)

It should be noted that we all have the same ip address

Am I hitting an admin session limit?
is there a max users from same Ip limit?
can I somehow whitelist an IP address so that it does not hit the max attempts?

Users with admin permisions don't seem to have problems, only my wholesale user group (which has 6 users)

You haven't mentioned your OpenCart version or what extensions you have installed?

Yes I did when I posted the question in 2.0

well, there are 12 different subversions of this, for some unknown reason.