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For me, the problem is with the Amazon appstore app stopping. I have uninstalled this from my phone and I have yet to get another "blip" that I described in my original post.
I found this by using another device to record a video of my phone when I opened the Amazon Kindle app. After a few seconds, I got the screen blip and Kindle exited and returned to my phone's home screen. By advancing the video frame-by-frame (or second-by-second), I found that a small screen flashed up that said "Amazon appstore keeps stopping".
I have not investigated why the Amazon appstore keeps stopping, but removing it has so far corrected the problem I reported in my original post.
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