you'll want to confirm in the Messages list of the logs that there was a 'Set-cookie' header in the originating response during the simulation (of 1 user by verifying the scenario). also, try using the named variable you saved the cookie value to in the URI of a subsequent request, just to prove that the variable was indeed initialized. variables that are not initialized will cause cookie replacers that use them to be skipped. upon re-run of the test, check what was in the URI of that subsequent request, if indeed the cookie variable was initialized.
