sleep tracking

My sleep tracking is bonkers! It used to be spot on but lately it will not recognize when I go to sleep (last night 10:40). It says I went to bed at 12:52am! When I used to edit my sleep, it would recognize that I had slept during edited time. Now I edit the real time I went to sleep and it just shows that Iwas awake from 10:40 - 12:52! We just got a hot tub and use it just before I go to bed. I take the VVS4 off when in the tub and put it on my pillow so I remember to put it back on before sleep. Is the soak doing something to my body that is causing the Garmin to think i am still awake? Stress and heartrate are fairly active from the time I put the watch back on but movement is totally flat UNTIL 12:52! What do I need to tweak in the Garmin in order to get more accurate readings. My sleep habits suck and motivation by sleep tracking is one of the big reasons I bought this tracker.