I created a ‘full’ backup against my most important folder tree – about 250 GiB, containing about 50K items. It took far longer than I expected, but did complete. I did not use checksum. I did specify that the folder tree was to be checked for changes every 12 minutes. I then made a single file change as a test – an important change to an important file. 4 hours later BIT had still not made an incremental backup, but rsync has been running, consuming about 1% of my reasonably fast CPU throughout that time. A simple running of FreeFileSync comparing the current folder tree with the full backup made 4 hours ago immediately shows the one file I changed, but BIT has not seen it – meaning that this change might be lost if I restore my ‘original’ folder tree now. This loss of data is not what I expected. Why does it happen? I also notice that BIT did not backup a file of type .kra~ (a Krita file). This too appears to be an example of data lost by BIT. Why did that happen?