Since my OP:
1. Full internet came back for about 5 hours (until 4 pm on 5/9), then "broke" and stayed "broke" until bedtime.
2. Since 5:30 am today, 5/10, I have full internet again. (I even extremely, foolishly allowed a Win 11 "Because It's Tuesday" update this morning. Immediately regretted doing so, because what if internet fails and my laptop enters an infinite update loop?; but I digress.)
3. I checked for loose connections. There were none. There were also none 3 years ago when the same scenario occurred, only that time a Cox tech mumbled something about a database setting on my account/connection getting flipped/fat-***. His actions to correct said database completely and immediately restored my internet access.
4. After both Darkatt's post and reading Tom's Guide re docsis 3.0 vs 3.1, am convinced that DOCSIS 3.1 is NOT required for anyone not needing higher speed/performance than 3.0
5. I conclude that some snafu at Cox similar to 3 years ago caused my temporary loss of internet. My cable tv feed on same coax is fine. Cable tv is MASSIVE amount of digital video, Internet traffic is none such.
6. I wasted $140 on a refurbished docsis 3.1 wifi router because of Cox tech advise. Let's see how will it works come Monday, as shipping was extended three additional days. Thank the Almighty for His role in my internet now working.
