I have a Western Digital Network drive that is shared with my Linux Mint machine.
I'm having a very strange issue where I'll be moving a large file over to the NAS (an ISO image from the net, through a torrent, downloaded directly to the mounted NAS) and once the machine turns off the monitor for power saver mode, the mount drops, and I lose connectivity to the NAS entirely.
I know this sounds like a problem with the NAS itself, but I can download this same file with my windows machine without a problem at all.
does this issue make any sense?
let me know. i can give more detail if needed.
thanks in advance.

you need to check while power saver mode system is not turning off ethernet port power. that could be the problem if it is only happend while power saver mode.

also make sure about HDD. you need to verify that only monitor goes to power save mode not others.