I had the same problem as you Marcin (setting sendfile to ‘off’ did not fix the problem). You are correct that it has something to do with vagrant’s mounting of the application folder. I had the same setup and debugged for 3-4 hours only to realize that this problem happens when i edit the application files from the host (when i edit within vagrant’s vm it is totally fine).

Then i googled around for solutions for mounting the NFS correctly. I found this configuration (for Vagrantfile) works with editing application files from the host computer:

config.vm.synced_folder “./”, “/vagrant”, type: “nfs”, mount_options: [“nolock”, “vers=3”, “tcp”]