Thanks for the suggestion! I actually tried `pragma synchronous=FULL;` & `pragma synchronous=EXTRA;` after your comment. So far problem stays even after using the synchronous pragma. I tried different ways for step 8: - kill app itself - reboot device via POWER system button - removing battery from device. Result is always the same - after re-opening app there are some transaction lost. Which i totally don't understand as soon as wal hook shows, that pages been commited to WAL journal file. Why don't they appear after checkpoint?