thank you for the fast response!
I'm reading epub files. it happens with every epub I testet. epubs are in a directory called epub witch is in the base directory (not my documents directory).
I used this jailbreak
https://www.mobileread.com/forums/sho...d.php?t=198446
then installed the screensaver hack
then I installed exactly as you described
fw is 5.3.4
kindle is a paperwhite wlan (bought in the us)
edit:
I just moved the epub directory into the documents directory
cr3 crashed when trying to start
so i made a hard reset (removed the number lock too from the device)
and now it seems to work perfectly.
edit2:
found it. it is the lockscreen. while i'm typing in my password cr3 is running in the background and reacts on my typing on the screen.