Safari 13.1, which uses Adobe Flash(most current version in use, Xfinity is only stream that requires me to use Flash). If I open Safari, go to Xfinity Stream, and then open another tab in Safari, do anything etc, go back to stream, it refreshes after about 2 seconds with no input other that getting the fous on the streaming tab. Spoke with Apple support. Not a known issue. My Macbook Pro version of Catalina is 10.15.4. This worked as I would expect prior to an auto update on Catalina. As a course of troubleshooting, I tried on my new IMac, Catalina 10.15.3 with the exact procedure of, open Xfinity Stream, open another Safari tab, read whatever, go back to Xfinity Stream, no issue. Does not affect other streaming sites in Safari. Ok so i went a step further and loaded Firefox. No issue. Apple is making engineering aware. Has Xfinity seen this too? It is like it has to re-establish a connection with login info for a page/tab already running. Just an annoyance, and I want to use the native Safari over any other browser.
I have the exact same problem. Worked with Apple Support and they elevated the issue to their Tech team. They will be following up with me on April 16.
Good to see that I am not the only one as they were leaning toward it being a user account issue.
I have been wondering for over 3 years now about this.
I noticed when I updated to macOS 10.13 I started getting broken code sent to Safari (seems like the site reads 10.13+ as 10.1 and so a 480 video hits the CPU hard when I can stream a 1080 video on anohter site and the CPU usage is under 8%. Chrome gets lets Chrome code but when I try to mask as Chrome there seems to be Chroimum only coding rather than the feature detction they should be using.
I have to force the video playe to use low quality so I don't hear the fans due to the old code on the site. I looked at some of the site code and it is browser sniffing for Netscape or Windows 3.11 amoung others. Still see the same bug in 10.15.x I have have reported it to Comcast mulipule times, sent photos and videos of the bug and still not been fixed. Other browsers are getting a HTML 5 video player and Safari is stuck with a video player that runs like Flash Player on Mac OS X from 2003 performance (extremely bad).
I have also let Apple know.
Same issue. Only started today as streaming was functional yesterday. No Apple updates installed within that time frame. Error TVAPP-00210
Customer Service Diagnostics
Build number 9
OS Mac OS 10.14.5
Browser Safari 12.1.1
Flash version 32.0.0
Status in home
Entitlements clinear, tve-vod, cvod, tve-linear, est, transactions
Last fingerprint cloudtv_web_polymer_5.19.1_prod_1589XXXXXXXXX_XXXX
Stream provider primetime
Note: I cleared my History but that didn't seem to work, so I decided to check out preferences.
This worked for me:
1. Go to the Safari menu (top left) and select "Preferences..".
2. Click on the "Advanced" tab.
3. Deselect (uncheck) "Stop plug-ins to save power"
4. Make sure that Xfinity.com is set to on in the Websites tab, for the Adobe Flash Player. (update Adobe Flash Player if it hasnt been updated in a while -- I did not update mine v32....
5. Restart Safari; and go check the streaming for your channels.
SUCCESS!!! Hope it lasts... 😉
I surmised this might be a flash issue with the latest mac-os update to Catalina 10.15.4 after seeing FLASH icon appearing between every re-sign on. So I unistalled flash and reinstalled the latest version (selected by my mac), and it worked! No more closing of the xfinity streaming app, I can now move seamlessly between streaming and other websites and back!
Set Flash Player to auto update in the Adobe Flash Player preference pane.
You have to allow Flash Player on the site as Safari users are sent an acient video player (I found that it reads macOS 10.13 and higher as 10.1 (reported that to Comcast about 3 years ago).
Other browser get a sitghtly broken HTML5 video player (Chroiumum DRM spikes as much as the website tab playing the content)
Should note that Comcast has less than a few months before browsers remove Adobe Flash Player support and Adobe has a EOL date for Flash Player near end of the year.
I can stream 1080 HD and 4k on other sites with no CPU spike but I can't even stream 360 resoution without a 80%+ CPU spike on the site due to broken old code. The code on the xfinity site runs like it was last updated for IE6 in about 2004.