connecting apps to my router

I have xfinity internet services and here is a summary of the issue:

1) built house in 2018 and installed xfininty internet in home on day 1

2) all house apps worked fine for the past 2 years

3) starting about 3-4 weeks ago my camera app (SPECO) would not connect to the home internet - I have hardwired cameras from a vendor, they are not comcast cameras

4) I have sonos music system in my home that runs off the internet and will not connect

5) my ring doorbell and MQ (garage door opener app) will not connect to the modem/router

6) my lutron (light controller), reolink wireless cameras, remote access to my alarm system app and a few other things work fine.

7) I have shut off my security settings in the router to allow port forwarding

😎 I reduced my security protection to lowest level

9) upgraded my modem/router to the latest technology, version 8 last week - same issue

9) I was told comcast recently enhanced their security protocols. not sure if this has something to do with it. 

10) called customer support many times, hours on phone, they escalate it and they are supposed to call us back, no call received at all.

I am not certain what is causing this but it is very frustrating and confusing. my wife and I are both fairly savvy with IT issues, no less than average, and this problem is baffling. Any advice would be much appreciated.

Thank you,

Jeff