Using version 1.2 from stable ppa, on Ubuntu 19.04, backing up to local drive, sometimes files are being written to the snapshot with the wrong permissions. This makes itself known as after adding files and doing a snapshot if another snapshot is performed then sometimes files are modified showing permission differences. I have analysed one of these and see that for the orginal snapshot the permissions in fileinfo.bz2 do not match those in the written file, so I see

$ ls -l 20190504-162212-796/backup/home/colinl/tobackup/gitrepos/bin.git/objects/08/e1c829f014423d7eaa09b2e48643f32eff54b5 
-rw-r--r-- 1 colinl colinl 185 May  4 16:20 20190504-162212-796/backup/home/colinl/tobackup/gitrepos/bin.git/objects/08/e1c829f014423d7eaa09b2e48643f32eff54b5

but

$ cat 20190504-162212-796/fileinfo.bz2 | bzip2 -d | grep e1c829
33060 colinl colinl /home/colinl/tobackup/gitrepos/bin.git/objects/08/e1c829f014423d7eaa09b2e48643f32eff54b5

and I think 33060 maps to 100444 which is r--r--r-- which is what the source file is.
After running the second backup fileinfo still has 33060 but the permissions in that backup are r--r--r-- as they should be.
I can make the log for the first backup available if necessary but I would rather not do it publicly. There is nothing obviously odd for the entry for that file.