Metronome beeping irregularly on Forerunner 970

Hi. I had Fenix 6 pro for 5y and used the metronome during running at 168, beeping every 2nd step, i.e. for every left or for every right leg stepping.

But on the FR970 its not a consistent beep? I tried changing few beets up/down - same result - inconsistent beeping: There is a pause every now and then it would get out of time and then I’d get a double beep that wasn’t in time with the vibrate. Thanks