Network attached storage file-writing problem

I have a file-writing failure on an older Quantum Snap Server (network attached storage device) connected by RJ-45 cable to a switch which is also connected to my computer running Ubuntu 20.04. I can successfully create directories, use “touch” to create files, delete files and directories – everything, it seems, except write data to a file. The simple example command, echo “hi” > file-name, doesn’t even produce an error message but it fails to write “hi” to the file. I’ve google-searched again and again for suggestions and adopted some of them into my mount command here:

sudo mount -t cifs -o rw,username="guest",password="",vers=1.0,noperm,file_mode=0777,dir_mode=0777,gid=1001 //192.168.1.5/share /mnt/nas

I’ve installed the cifs-utils package on Ubuntu.

I need a network solution.