After a day dedicated to finding a solution to the problem, I managed to understand why this happens,
but not the cause.It does not affect the password and permissions, also because the same folder that is inaccessible with HiMedia, however, is accessible on the network with any PC connected to the network, so I exclude a problem of permissions related to Windows 10.
My configuration consists of 2 Silverstone storage boxes, each box can contain 4 HDD and are connected to the PC via USB 3.0 and the PC is connected to the network via LAN to 2 HiMedia units.
https://www.silverstonetek.com/product.php?pid=424&area=it&pid=424

The connection of the boxes is via USB3. 0 of which one is connected directly to the USB3.0 socket of the motherboard and the other is connected to an ORICO Booster card, since the other USB 3.0 sockets are occupied by other peripherals.
http://www.orico.cc/goods.php?id=4896

The box connected to this booster card containing the HDD with the shared folder is detected with a password from Himedia, but not from other PCs connected to the network.
To do another test I disconnected the box from this booster board and connected it to the USB 3.0 socket on the motherboard, now the shared folder is detected without a password from HiMedia.The problem is the USB3.0 booster card, and I can not understand why connecting to this booster card HiMedia asks for the password.
I performed another test by sharing a multimedia folder in usb memory.
By connecting it via USB 3.0 HUB,
I obtained a password request from HiMedia. (However accessible from another pc on the net.)

By connecting the USB memory directly to the PC,
no password is requested from HiMedia and the file is played normally.