AEM Air/Fuel gauge seems to be non responsive

[Kern Dog]

Years ago on the advice of a fellow car guy, I installed an air/fuel gauge. I was having detonation issues and thought that the gauge could help me tune my way out of the problem. Over the years, I have enjoyed having this gauge because it showed in real time what was going on. You could see it move around with even a 1/4 turn of the 4 corner idle mixture screws.

Lately, the readings have stayed in the 14.4 to 14.8 range which would be great if I was running 100 % pure gasoline but I'm not. We have (Up to 10%) ethanol here so the numbers should be in the high 13s at idle and cruise.
The numbers have stayed in a narrow range lately. Before, they would run into the mid to high 11s at WOT. They would be real lean at cold idle.
I'm curious if the lazy response I'm seeing means the oxygen sensor is going bad or if the gauge itself is to blame.
Where are the gurus on this stuff ?

 

[1 Wild R/T]

Cheaper than Summit
https://www.amazon.com/Bosch-Automo...6f139758e6addcc250a552a&qid=1758864754&sr=8-3

Much cheaper than Amazon but seems to cheap to not be a Chinese knockoff

https://www.ebay.com/itm/405541440304?chn=ps&_trkparms=ispr=1&amdata=enc:1sWSC1f6BR8ezQqre3bVk2A34&norover=1&mkevt=1&mkrid=711-173151-913341-5&mkcid=2&mkscid=101&itemid=405541440304&targetid=2437617225824&device=c&mktype=pla&googleloc=9032278&poi=&campaignid=22904786827&mkgroupid=182643131263&rlsatarget=pla-2437617225824&abcId=10415532&merchantid=5623123187&gad_source=1&gad_campaignid=22904786827&gbraid=0AAAAAD_QDh9ZB3TmLqXO29yUvACokzBjD&gclid=Cj0KCQjw0NPGBhCDARIsAGAzpp3R3bRvNHs1iWgIMmpccU2uap10CDnJKOUDuiIse7a0ku7hziQi_NYaArDeEALw_wcB

And yes your sensor has likely died...

 

[Kern Dog]

My bonehead logic has me thinking that a dead sensor would show ERR or a blank display. I bought this gauge well over 10-12 years ago.
I'll drive it and see if the numbers move around at all.
The car runs great. No smoke, no stumble, no detonation. It rarely ever smells like fuel either.