Steps

My steps data disappeared from previous day and it happened third time in a month. Yesterday I made about 11 k steps and it was seen on my watch when I went to sleep. But next day in the morning when I synchronized my step data, it showed 0 steps like I didn't walk at all previous day. My account is connected only to one device, so it is not due to synchronisation to wrong place problem. As this is not the first time it is happening, I want to understand why such errors occured and what can I do to get those step data back?