[ottischwenk]

d:\_Reader-Smartphone\ADB>adb shell
BOOX:/ $ cd /storage/emulated/0/Calibre_Companion
BOOX:/storage/emulated/0/Calibre_Companion $ time ls -Rl | wc
  16550  240759 1746789
    0m47.39s real     0m00.60s user     0m00.89s system
BOOX:/storage/emulated/0/Calibre_Companion $ time ls -Rl | wc
  16550  240759 1746789
    4m09.59s real     0m01.91s user     0m09.67s system
BOOX:/storage/emulated/0/Calibre_Companion $ time ls -Rl | wc
  16550  240759 1746789
    4m10.37s real     0m01.89s user     0m09.95s system
BOOX:/storage/emulated/0/Calibre_Companion $ logcat -f /storage/emulated/0/aa/logcat.txt
^C
130|BOOX:/storage/emulated/0/Calibre_Companion $

The first time command was after booting the Tab Ultra.
Before the second, I loaded the Calibre_Companion folder to view the contents.
Before the third one, I turned off WiFi.
And then I created a logcat.txt while opening Calibre_Companion.
After I was able to see the content of Calibre_Companion, I checked "aa" to see if there was logcat.txt.