internet stutter choppy

I am having problems with internet service quality.  This occurs on multiple devices (TV, iPhone, iPad, Microsoft PC).  Any streaming video will have stops and restarts, buffer reloads, dropped connections.  Simple web page use has occasional non-response errors.  Streaming services include ROKU, Peacock, YouTube, Xfinity, MLB, using either ethernet or wifi connection.  I Have gone through all the checks following the online scripting, and all hardware checks out okay everything has had full power on-off cycles, all drivers are current.  I have Xfinity digital service and gigabit internet.  This is very disappointing!

There was storm damage in my neighborhood several weeks ago, and this has been particularly bad since then.  

I am a retired license Professional Engineer, including a grad degree in IT, and considerable experience in design and application of ethernet-based embedded systems.

I have tried everything I can to get a response from Xfinity, but these problems don't fit any of their automated scripts.  Is there anyone who can look into the poor quality of service and advise me on how or when it can be improved?

Jon