Jarvis 16.1 versus Krypton 17.0 on fire stick & fire TV

I was running Jarvis 16.1 on my Fire stick quite happily (on the whole) and last week upgraded to Krypton (didn’t do fresh install just downloaded it on top of Jarvis, hence retained all my settings)
Initially it run OK then just stopped loading. When I tried launching it from the main menu, nothing happened. I wondered if the cache needed clearing (though I had 4gb free). After clearing the cache I got the ‘first run screen’ but it went no further. I therefore uninstalled it and did a Krypton fresh install. However all I got was a repeat of the above.
I have therefore done a fresh install of Jarvis 16.1 (lost all my settings, as didn’t do a backup,,,not even sure how to) and it is running fine again. I am disappointed as I have been eagerly awaiting the stable release of Krypton
So I am asking all of you out there who use a fire stick, what has been your experience. Have you encountered problems or is it running without a hitch on yours.

My next question is that I am considering buying an Amazon Fire TV, so for all of you who have the Fire TV, how does Krypton versus Jarvis run on yours,

Thanks in advance