Redirect issue with 2 installations to the same domain

I have install the phplist in 2 folders (and 2 db’s) for one domain.
So I have

this 2 installations has specific db access and specific admin credentials.

When I login to and create campaign mixed up in the last step and brings the list of
Why does this happen?

Is any solution of caching?

@stavroch Possibly a problem with the session naming. You can try adding a line to each config.php to give each instance of phplist a different session name