comcast email doesnt work with iphone or ipad

it says the username or password is incorrect but it is the same username and password i use on laptop with no issues (on comcast.net site)

have reset password 4 x and it works for a week or so and then the same thing starts all over again.  Comcast says it is my devices, but i have 4 other types of email accounts on my devices that work just fine. 

have to stop using comcast email i have had for 15 years and switch over to gmail.