3 beeps from Dashboard

[metalsman]

19 T1 Silverado LT Z71 with standard radio, All star package. Jan 2019 build, have 7500 miles and about a month ago I get 3 buzzing beeps from deep in the dash, randomly. sometimes a single one on startup. Even with radio off I get it about every half hour or so but no consistent repeat. no warning lights or message are showing or occur when it happens, nothing turns off...just very annoying.

 

Any clues?

[DaveHC]

mine does that if I go faster than my set speed reminder is set on, set on 80 and took a few times bumping passed that to figure what the beeping was about.