Have you first tried power-cycling / re-starting the device by unplugging it for a minute ? No joy ? Try hard resetting the device to factory defaults by pressing and holding in the recessed reset button on the rear (or use the WPS button if it doesn't have a reset button hole) for 30 seconds. This can sometimes clear up some weird behavior issues. You will lose any customized settings, and they will need to be re-configured from scratch if you do the latter.

Good luck !

Thank you so much for taking the time to reach out to Xfinity Support @user_142px4!  We are so glad to hear from you and want to help in any way that we can to ensure you are having the best experience with your service.  No worries!  You have reached out to the right team to get things squared away.  Can you tell me what errors, if any you may be receiving when you attempt to log in?

@user_142px4 

So have you tried power-cycling / resetting it to factory defaults yet ?

And try just using http://10.0.0.1 and drop the /index.jst path/anchor part.