GPG Sync 0.3.5 on Windows 10 - works up to 50% of keylist and throws error

[iwonazytkiewicz]

Hello GPG sync people
GPG Sync 0.3.5 on Windows 10 - works up to 50% of keylist (sometimes 30, sometimes 44...never more than 50though ) and throws error - Keyserver error.
Then starts immediatelly from the beginning. And so on, and so on.
Never had it managed to finish. The same version of GPG Sync on MacOS with the set of identical settings - works fine.
Did anyone else face similar issue ? Is there some timeout for this process on Windows? I have no debugging capabilities on this windows env unfortunatelly (nor sufficient windows knowledge) - so any suggestion is welcome.
Cheers!
Iwona