no folders access on another network [SOLVED]

[aar]

home network 10.20.120.0 255.255.255.0, NAS DNS-323-B1 Alt-F 0.1RC4.1 on this network (10.20.120.119), router Xiaomi MiMini Padavan firmware.

in this network works without any problems.

router is OpenVPN server.  To OpenVPN server connected a few plain clients, and one clients with another network (10.20.121.0 255.255.255.0)

if I try to join to NAS from any OpenVPN clients - Windows error message (windows can not access to \\10.20.120.119). Diagnostics button returns "on this computer missing one or more network protocols"

but ping from any OpenVPN clients to NAS is OK.

clients Win 7, Win 8.1, Win 10 and a few NAS on linux clone

all other computers of these networks detected each other and with the original NAS firmware no such problem.

What could be the solution ?  This is SAMBA problem ?

UPD if I change the mask in Host Setup on NAS Alt-F, to 255.255.0.0 (10.20.0.1 - 10.20.255.254) - not ping from any OpenVPN clients...

UPD SOLVED - in Alt-F WEB UI --> Services --> Network (Network Services) --> Configure button on Samba Server (Windows) --> Adwanched button (bottom of the page) --> Clobals button --> in hosts allow section add the relevant network addresses (for example: 10.20.121.0/255.255.255.0, 192.168.0.0/255.255.255.0  etc.)   enjoy !