Only when Search for Sesions:count > 0 is the condition that detects duplicates. If there is another session that has the same information as the one that is being created, then shows an alert and should end the workflow (or in that case, should not pass to the next CE).

Right now, when the bug happens it is evaluating:
Only when Search for Sesions:count > 0 as True
and
Only when Search for Sesions:count is 0 as False, but just from the CEVerificar Duplicados, because once evaluates it as False, the Workflow ends.

In order to create the session:
The Only when Search for Sesions:count > 0 condition from both CE should be False
and
The Only when Search for Sesions:count is 0 condition from both CE should be True.