A three days ago the watch battery started draining by about 50% during the night. Daytime battery drain seems to be a a slower pace. Last night I charged it to 100% before bedtime then wore it as usual during the night. I woke up to 56% battery. I've been using the watch for about 3 weeks. I don't believe there was an update in the last few days. I have changed none of the settings in the last few days. What could be causing the rapid battery drain?