Linux desktop client doesn't notice file changes sometimes

I am testing Linux desktop client under Ubuntu 16.04. It is installed from, latest version (2.5.2git). Everything works smoothly, but sometimes client doesn’t notice files added or deleted from some directories. For example, I have created a directory “Test”, moved some picture into it almost instantly, directory was synced, picture wasn’t. There is nothing in logs when this happens. Also, the only way to force client actually upload the file is restart the client. When restarted, it finds the file and uploads it successfully.

Should I report this somewhere else?