We are having the same issue with our kids HD 10 fire tablets as well. Game was crashing & having trouble with booting our kids out of servers & their own worlds. My oldest uninstalled it & is trying to redownload it. It gets to the 3/4 on the download then stops & gives the error "can not install" & tells us to try again or contact Amazon. Guess it could be due to the download server being overwhelmed by a lot of people trying to redownload & install the app.
I just bought Minecraft on the Nintendo Switch a few weeks ago so I could play cross platform with my kids. It locks up the whole system when it freezes. Freezing occurs after about 10 mins(sometimes more, sometimes less) & seems to occur no matter what I/we are doing: playing solo, cross platform, split screen, etc. It especially does it worse if playing in a Mario Mash-Up created world. I haven't noticed if it was auto saving at the time but will watch closer the next time we try to play it. With all the various issues with having it on the Switch, I'm regretting buying it & should have just got it on the PC or XBOX.