iTerm2 tabs don't start different terminal ses

Question

I've installed iTerm2 on all of my computers (OS X). On each of them, when I hit cmdt, a new tab opens and I get a new session... except for one of them. On this one, when I hit cmdt, a new tab opens, but it's the same session. Anything I do in one tab is reflected in all of the tabs.

I've read through the preferences a few times and haven't seen anything that would control this. Googled it too.

Anyone know what's up here?

EDIT 1

To clarify:

When I first start (only 1 tab) and do an ls I will see the directory structure in the window. When I launch a new tab (tab 2), both tabs will be a clean terminal session. When I do nslookup google.com I will see the nslookup output in both tabs. When I launch a new tab (tab 3), all tabs will be a clean terminal session. When I do curl google.com I will see the the curl output in all three tabs. When I close tab 3, the remaining two tabs show the nslookup output. When I close tab 2 I am back to the original ls output.

In the above scenario up to tab 2, if I drag tab 2 to it's own window, tab 2 correctly has the nslookup output and tab 1 correctly has the ls output.

If I don't use cmdt and instead create new windows with cmdn this issue doesn't occur.

Answer 1

Menu item: Shell / Broadcast Input is not set to "Send Input to Current Session Only"