I didn't explain right, as I know what process, but quartus will launch multiple processes during a compile. Open the GUI and quartus.exe shows up. Hit compile, and quartus_map.exe shows up, then quartus_merge.exe, etc. Quartus_sh.exe is the shell, which means you're running from a script. Can you give more details how you're running your compiles, maybe attach your script, and that might show what's going on. When running a compile from command line, the simplest way, which I do all the time, is:
quartus_sh --flow compile --64bit project_name -c revision_name
(--64bit and -c revision_name are both optional, I'm just in the habit of adding them)