When it comes about signing in issues with your Comcast email account; users registered some common problem, we are listing few of them here.
 Forgotten password
 Password lost
 User name forgotten
 Loop log in page error
Apart from that, there is no such common sign out problem with Comcast email account. You simply need to click or tap on the sign out button. The only problem could be with your web browser or the network coverage when you find it difficult. If needed; you can call Comcast mail customer support toll-free number for any help.