Thank you for giving that a shot. Could you please try the 'Sign In' tab on the Xfinity home page via this link and let me know if it works. 

so that takes me to the page where i select "account" on top left to sign in, which takes me to a new login page, just like before.

https://login.xfinity.com/login?c_ds_na=c_ds_na%2Cc_ds_no%2Cc_ds_ts%2Cclient_id%2Ccontinue%2CmaxAuthnAge%2Cr%2CreqId%2Cs&c_ds_no=97E2DDC77268FA0117C7961F41AAAB0D&c_ds_ts=1652094949&c_ds_val=510F79E68944DA053AEC4C5E0AC4B0C5B68FC37932A75011564CBAB376ABDA74&client_id=x--d2.prod.cmsplatform&continue=https%3A%2F%2Foauth.xfinity.com%2Foauth%2Fauthorize%3Fclient_id%3Dx--d2.prod.cmsplatform%26response_mode%3Dform_post%26redirect_uri%3Dhttps%253a%252f%252fjss.xfinity.com%252fsignin-cima%26response_type%3Dcode%26scope%3Dopenid%2Bprofile%26state%3DOpenIdConnect.AuthenticationProperties%253d3BuzwmcKDzcauNa6ssSn3M_oFMxsi0ADjm-BBb9-awNkp_pyfCJoGEcXFZSMZQCNwxzspPvdD56WQiR5xdkF9ZIOVO0VDosBCsyWKYjbos07br5iVpdND3bKZu6LlrY8LeNDgKHOdTALaf9QGrl3DozVY-ZmhTwK7ZrChCwRDmPeSN6dq8R1qeLUB7UcQ-k0p--yK34MF41qyqQhjMR7blY5G1XGHfI3vtSAx75fKXxXnSEH7naQop2suOImDkYX7LLMXX6h_9Azaofk5-sapTp60mWpEu682aZ3Ccs-krXcQ-sF8ZikKDz49pZp0-l0KUbQ-7OwoCeb22vU1eoIJDMT4qUswcx5lAuRvPUShloselTUaUL1b7b-_GCehWoCMZRq_i4k6E1G8JUGx0IR1tofAXU%26max_age%3D9000%26response%3D1&maxAuthnAge=9000&r=comcast.net&reqId=484235b2-a86b-408f-9397-6d84aa509d1b&s=oauth

the url of the actual link you sent me to is:

https://my.xfinity.com/?cid=cust&linkId=164251307

when i select pull down menu on the above page and select signin on bottom right, this is the url i get sent to:

https://login.xfinity.com/login?c_ds_na=c_ds_na%2Cc_ds_no%2Cc_ds_ts%2Cclient_id%2Ccontinue%2Cr%2CreqId%2Cs&c_ds_no=B795F95EC0DF5DE327F1D862CC183C4E&c_ds_ts=1652095515&c_ds_val=BA25970B92F4BA589D30297F2E7595B8F45BDAED495BFAA61984C4D2AD7F225F&client_id=my-xfinity&continue=https%3A%2F%2Foauth.xfinity.com%2Foauth%2Fauthorize%3Fresponse_type%3Dcode%26redirect_uri%3Dhttps%253A%252F%252Fauth.xfinity.com%252Foauth%252Fcallback%26client_id%3Dmy-xfinity%26state%3Dhttps%253A%252F%252Fcustomer.xfinity.com%252F%2523%252F%253FCMP%253DILC_signin_myxfinity_re%26response%3D1&r=comcast.net&reqId=cada5f85-ed89-4b74-a4fe-66005dcff7f9&s=oauth

Thank you for sharing that with me. I was able to replicate the long URL on my end as well for the actual 'Sign in' page so this seems to be a normal function. With that said, this is why we always recommend logging into your online account by accessing the links provided on our Home Page. If you happen to receive a link in an email or are unsure of the legitimacy of the link, we highly recommend reaching out to our CSA (Customer Security Assurance) team so that they can look into it further.