My Lily 2 Active has automatically turned off sleep mode (not tracking my sleep) every day the last 4-5 days. Heart rate is set to on as is the pulse ox. I am not disabling sleep mode each day and it is by chance that I look at it before bed lately and see it is in the “off” or “silence” mode to not track my sleep. Why does this keep happening? I have reset the watch and read the manual, without resolution. I purchased the watch new about four months ago.