During the activities the connection between fenix 7 x and the external heart rate scosche rhythm 24 interrupted many times for 1'-2' and reconnected automatically again..... please some help....
Perhaps this may help: connection problems scosche 24 by BT - fēnix 6 Series - Wearables - Garmin Forums
BTW, if you use it for swimming, then the connection won't be reliable anyway, regardless whether connected over ANT+ or BT. Radio waves do not travel well underwater, even if you have both devices close to each other. For swimming you need a HRM with the Store & Forward feature, such as for example the HRM-Pro