Initially I didn't know about it and when registering for first dose I was trying to register in that app and then realised it but to be fair if you are literally going to give same name to that thing everyone will get confused
But now I am trying to login in cowin portal for second dose but otp never comes trying from 3 days
For me as well OTP never received for CoWin app. But I was able to Register through PC browser. Later same details were displayed in Aarogya Setu app with same mobile number. OTP is sent instantly when trying to access Vaccination section in Aarogya Setu app.