We see only Windows 10 clients loosing connection to CIFS shares sporadicly. Failure means something like 'Path is not available' but network seems to be fine as only those Windows 10 client are kicked of the CIFS connection.
Failure started some Windows10 major patch release updates ago.
Thanks, i already saw that, but difference is that we are able to connect but loosing connection sometimes. The wiered thing is that we had no problem at the beginning of Win10 but got that behaviour with some of the patch releases (don't know which exactly).