Save and switch cohort is not working when the new cohort name is duplicate of existing cohort name

[tongy-msft]

Save and switch cohort doesn't do any thing if I want to create a new cohort with name cohort 1 while I already have an existing cohort with name cohort 1 . There should be some message bar to indicate users that (1) cohort name already exists, create another one. or (2) Do you want to overwrite/replace the existing cohort with the new cohort. Same issue for Save button if there is a name conflict