smb sharefolder not reachable over just one of two win10 clients (0x80004005)

I have a little confusing problem. I have two samba server running. The first one is an little NAS direct on my router running and the secound one on my little pi3. if i try to connect from my win10 workstation over LAN or WLAN to the NAS on my router it works fine. if i try to connect to the pi3 i get the 0x80004005 error. At next i tried to connect over my laptop also with win10 on it over LAN and WLAN Segment at both NAS and pi3 and it works fine. i tried also an virtual machine on my workstation, also win 10, to connect to both NAS and pi and look at that, it works. But that confuse me, because i thought thats an network card problem, but it isnt. it looks like its an problem on my win10 system, but i cant figure it out which options has to be changed. The standard options like firewall off, changing network to private, deactivation ipv6, activating sharefolder view options were did without positiv resolutions. an tip would be cool. thx