laravel authentication mix user seasion

I have a larval project v 5.6.26., and the season is working perfectly when the user is logged in from inside the network or from their own network, however, there are some group of users comes from different branches of the company in different cities and all there request comes with the same IP address and their seasons are mixed together(only those users from these branches).

I am using the auth for the authentication.

any idea what could be the problem??

via Chebli Mohamed