I'm watching this thread because I too am having this issue. Apple Watch series 3 with LTE. Latest update. This is my first Apple Watch so I thought maybe I was doing something wrong and just kinda forgot about it (Watch was a Christmas gift so I'm still learning how it all works) until I seen this thread here. I too do not have anything scheduled in my calendar and I have it set to remind 3 times a day. Some days I've gotten none.