User equipment updates

I recently had a problem with my cable router. I discussed this with Motorola support, and they said that Xfinity downloaded changes to my router. I have questions about this:

**-->1. The firmware version on my cable router is now 7700-5.7.1.21. I don't know the version that it had prior to the upgrade, but the serial number is 2810-MG7700-30-6478. I bought the router, new, in January 2021. Can you tell me what Xfinity changed in my router?

**-->2. I missed Xfinity's notification to me about this update. It is not in my mail or email. How did Xfinity notify that they changed the operation of my router?

**-->3. I discovered the change when the update made my user id on the router unusable. I had to do a factory reset to access the router. This is a bug in Xfinity's update process. Will future updates also wipe out my user id and password and is there a work-around?

**-->4. Does the upgrade process also wipe out the custom configurations I put in the router? I had to do a factory reset to get my router to respond to a user id. The factory reset cleared my custom configuration.

**-->5. The router originally had a backup and restore feature, allowing me to save the configuration of my router. The change degraded the modem by removing this feature. How do I perform these functions with the change? This is especially important given that a change upgrade will require factory reset and subsequent re-configuration.

This unexpected, unannounced change resulted in loss of service while I spent my time determining the problem and reconfiguring my modem. I expect Xfinity to provide timely notifications of changes prior to the event so that I can be prepared. I also expect that Xfinity will not degrade my personal equipment without my consent or knowledge.