Unable to sync some files but not all


I encounter a strange issue since a little while with my NC19… I noticed that few files on my laptop were not showing up on an other computer (both have sync on same NC folder). I checked first on NC itself and these files appear properly. It looks to be a problem on the other computer and checked settings of NC client and also upgraded it from version 2 to version 3 but it’s exactly the same with these files not synchronised where client complains about: The downloaded file does not match the checksum…
I tried to do a clean and reindex using occ command line tool but problem still the same ! I have found only some very old subjects no more relevant about similar problems that stated to use occ to regenerate the checksums of files but command doesn’t exist anymore !
If it’s important, both sync clients run on Linux Ubuntu.

Thanks for your ideas, suggestions,