Use Ava bracelet, TTC. Need advice

Alright y'all. So my SO and I have been TTC since July of this year. I purchased the Ava bracelet 2 months ago and I love it. It's usually incredibly accurate and easy to read....until this cycle. Last cycle, it predicted my period and ovulation day EXACTLY. This month it is testing my patience. My fertile window "started" as normal. But for the past 3 days I've gotten up, synced my data, and waited patiently for the daily results. Well, each of those days the peak ovulation day moved from THAT DAY to the next day. Temp has stayed elevated for the last 9 days but for the past 4 days Ovulation test has been negative (I use the dip sticks). Has anyone had experience with Ava bracelet?! Please help me!! Why does it keep moving the days? ((I should say, it isn't shortening fertile window...just extending day by day..))