Apple Watch 6 inaccurate resting energy

My new appl watch 6 resting energy is inaccurate. Has a series 2 before and while I slept it estimated my resting energy and it was always between 1450-1550 per day which is nomad for my age n height. Now it does not record my resting energy when I sleep some days n when it does not give an estimate for resting energy while sleeping my resting energy for the day totals 909-1000 this is low for an adult. Is this something new with the new watch