I think I may have figured it out. I have been using the home button to exit when watching and it has been working to set the point at which I exited. Now it appears that it sometimes works and sometimes does not. But, if I use the back button to exit, it appears to work. Guess I will have to give it a while to see if that will continue to work. The home button appears to still work for Netflix. So I do not know who changed what. But for now, it looks like maybe I just need to remember to use the back button on amazon prime.
In general, don't use the home button to exit a channel. It's akin to pressing the reset button on a computer. The channel gets no warning and no chance to save any information. It may be ok sometimes, but often will not be.
Thanks. Guess I have been using the button for and "unsupported function". But something changed, but it appers to have changed only for Amazon Prime.
But, regardless, seems I probably need to always use the back button.
But I am a bit curious as to what happened to cause the change.