Multitenant - session expired

Hello,

I have successfully set up 2 sites on a VM running on debian. One site is set up as production and the other one I’d like to use it for tests.
I can access both sites on my local network (192.168.1.30 and 192.168.1.30:8069).
However, I cannot log in to both sites at the same time (fron 2 tabs in firefox for example), I get an error “Session expired. Logging out”.

I followed the multi-tenant setup on github but I guess I missed something…

— EDIT —
I cannot be logged at the same time within the same browser but it works with 2 different.

Thanks for your help