During run and bike - when I received performance condition notification, vibration start and finish at the end of first km or lap

Hi,

i have Forerunner 970, on latest sw version,   when I am running or biking, once I receive performance notification vibration start and is not ending until first km is announced or first lap is announced on bike. 

anybody experience the same or I have something wrongly set?

thank you for advice 

lada