I have Fenix 6s and indoor sports are a big disappoitment for me. I had a vivoactive and there was a distance quite accurate - it was based on steps maybe, I dont know. But Fenix 6s are horrible for indoor sports (the distance is a joke and there is even no record of total number of steps) - Garmin should do something about that. These watches are quite expensive and the indoor running activities such as tennis, basket or football are very popular. I tried everything - new activity, cardio etc., but nothing works...