your connection is not private problem

Ever since I replaced my modem last week I am experiencing the same problem.

Same problem here.

I had xfinity on the phone yesterday and we got disconnected right after I went through the registration process successfully for the 5th time.  Still having the problem.

My current workaround: when I get the intermittent error, I copy the url into a different browser and it works fine.  I switch between Chrome & Edge.  I also noticed, when switching back to the browser with the error after an extended period the page loads fine.  For some reason instead of using the site's Certificate Authority to validate a secure connection it is using register.be.xfinity.com (which says the certificate is invalid).

 Did you get new equipment recently?

Yes, I replaced the old xfinity modem with a new one.  I just spent a couple hours chatting w/ xfinity and I am awaiting a call back.  The tech I chatted with blamed it on my setup (which has not changed in 3 years).  My xfinity modem is configured with 10.0.0.1 subnet.  I have a netgear modem hardwired into one of the ports and is configured with 192.168.2.1 subnet.  I use the 10.0.0.1 range for TV's and Sonos - mostly wifi.  I use the 192.168.2.1 for computers and network storage.  Again, this setup has been working for at least 3 years without any issue.  What I find peculiar is that like the original poster, when I get the error, and check the SSL cert, it is wrong - rather than being the cert for the website, it is register.be.xfinity.com.  Also, if the error page is left open for several minutes - the error goes away and the page loads!

I have the same problem.  I am using Comcast modem.   Hope you find a solution.

My problems all started when I upgraded my internet modem.  They merged my internet and voice services onto the new modem and my phone stopped working.  My voice modem is in my basement.

A tech came out a week and a half ago and got that fixed but then my internet started acting up.  I believe they did the reverse and messed up my internet.

I went out of town and couldn't deal with it until I got back.  Finally got a tech out here yesterday and he swapped out my modem and supposedly fixed it.  They had indeed moved my internet to the voice modem (also a new device).  When they added the new internet modem they lost my old voice modem from their system.

But now things are flakey again.

I'm going to try replacing the coax and see if that helps but then I need to get in touch with support again.

How do you check the SSL cert?

Do you have internet and voice service?  Do you have separate modems for each?

On a hunch, I unplugged my voice modem and so far I have not had any internet issues.  Somehow it is conflicting with the internet modem.  I have another tech appointment on Monday.

I just went back to my old modem.  Has anyone solved this problem?  Do I need to return the new modem?  Is there a work around that doesn't take waiting several minutes for the page to load properly?  I have upgraded a few devices and have had trouble across the board with all of them.  Only website that would load was the comcast website.  

@Dsb893 

Please create a new topic of your own here on this board detailing your issue. Thanks. 5 month old dead now being closed.

this seems clearly an xfinity issue and I am surprised they havent fixed it so far... I am getting the same error after switch from xfi modem to getting my own moden

@ramaneshk 

Please create a new topic of your own here on this board detailing your issue. Thanks. Re-closing this incorrectly re-opened thread due to an error in the recent forum transition.