It took me a moment, but I found a solution
I tried with few computers and as I wrote previously I didn't have problem with Linux, I checked that Android devices also works. Problem was with my Windows 10 PC. Meantime I connected to OMV with two other Windows 10 laptops ... and they worked. So I waited for Windows 10 April 2018 Update hoping that it would fix the problem. But it doesn't. So I started looking for solution one more time...
First of all I found that my PC is with Windows 10 Pro, rest two are Home version. Than I tried to connect via 'net use' in command prompt not File Explorer and this gave me an error message I asked Duckduckgo about it and I found this link on MS Technet. There is described the same case there. To fix problem it is enough to run "secpol.msc" and go to Local Policies -> Security Options -> "Network Security: LAN Manager authentication level." and change from "Send LM & NTLM - use NTLMv2 Session security if negotiated" to "Send NTLMv2 response only. Refuse LM & NTLM". Click Apply and it works taadadadam