How to Restart a Live Program?

We recently relocated and used a streaming TV service from a local provider that allowed us to easily start live programs from the beginning, pause programs indefinitely, and navigate backwards.

Can we do this with Xfinity Stream?

I have searched and find articles suggesting we press "info" and may find the option to start from beginning.  We tried this and do not see the option.

I found another article claiming we may need "DVR Service".

We are using Xfinity as our internet provider and streaming to the Xfinity app on a Firestick.

I tried using the Xfinity app on our LG smart tv and it did not have any more features.

I called Xfinity support and was told I needed a "wireless box" to get these features.  So I went to an Xfinity store and was told they were a "partner store" and had no wireless boxes.  They suggested I go to a corporate store...

So I went to a "corporate" store and was told what I want is not possible.  The sales/support rep was rude and acted like I should know that "starting from the beginning" of a live program was impossible and would "mess up all the programming".  I'm not making this up.  Really?

I feel any digital stream is buffered and/or archived somewhere so enabling these features should not be rocket science.

What am I missing?