I've been experiencing this as well- seemingly with increasing frequency as they use their own "AMZL" delivery service. It's rapidly discouraging me from order

I've been experiencing this as well- seemingly with increasing frequency as they use their own "AMZL" delivery service. It's rapidly discouraging me from ordering things from Amazon if I'm going to rely on the delivery date. Or casually ordering things (i.e. via Alexa) that I might not be paying attention to the delivery of. I've had prime since it became available, and this is a very disappointing turn for Amazon from my point of view.