Some while ago Garmin introduced a feature where on bikes with eTap sensors connected, the Garmin head unit beeps when you shift onto either the largest or smallest cog on the cassette.
I have three bikes with eTap installed - one with the original 11-speed Red eTap, a second with 12-speed eTap AXS, and a third that has 11-speed eTap front and rear derailleurs, but due to one of the original 11-speed levers getting broken in a crash, I'm using AXS levers with the 11-speed derailleurs, a combination that works fine with up-to-date firmware on the levers (SRAM no longer have 11-speed levers available). On all three bikes the gear combination data field on my 1050 correctly shows the front and rear gears in use, and on the bikes that are either all 11-speed or all 12-speed components, I also get the beep when shifting to the largest/smallest cog, however, on the bike that is the 11/12-speed mixture, it stays silent. This seems a bit strange, given that it's actually the rear derailleur that communicates with the Garmin, and it's obviously communicating OK as the gear combination field gets populated correctly with the gears in use.
A second problem with the 11/12-speed mixture bike is that the data field that shows the battery levels for the shifters and F/R derailleurs displays the derailleur battery levels OK but just shows question marks for the shifter battery levels. The other two bikes show all four battery levels OK. However, that problem is probably due to a problem at SRAM's end with their interface between the 12s shifters and 11s RD.