Paramount Plus With Showtime - IMPOSSIBLE to Sign Into App with Subscription from Xfinity

So I renewed another annual contract and added Max and "Paramount Plus with Showtime" to my bundle for $5 a month each.  When I try to log into my new Paramount+ account through the app, it will not accept my Xfinity credentials, so I had to dig through the website to find the providers list, and it does NOT include Xfinity.  I figured to sign onto the Showtime Anytime app to obtain my credentials from that hoping it will work on Paramount+, but it does not properly sign on through the Xfinity provider link (possibly because the app has been phased out).  I called Xfinity and spoke to several reps who were super-confused and eventually referred me to Paramount+, then I called them and they confirmed this is a known issue because Xfinity never established a proper provider link with them, thus making it impossible to access their full app services through mobile, online and cable boxes.  Lastly, an Xfinity store rep, who was also stumped by the issue and promised to coordinate with the corporate office, suggested I used the Xfinity Stream app to access Paramount+ with Showtime content.  However, it does NOT include all the content that the app contains, such as Mission Impossible: Dead Reckoning.  PLEASE FIX THIS ISSUE!!!