Stucked request on IIS 10 when we require or accept client certificate for authentication

We have issues with stucked requests on IIS 10 only when client certificate is Requireed or Accepted on a specific site (SSL Settings).

All requests are stucked in »BeginRequest« state for about a minute. While those requests are on hold, process "IIS worker" uses high percentage of processor (more requests - higher the CPU usage).

IIS 10 Stucked requests

After one minute each request fail with status 500 and error code: "An operation was attempted on a nonexistent network connection.(0x800704cd)".

It's interesting that the client (Firefox) gets the response from IIS server everytime but each of those requests still remains in »BeginRequest« state on IIS for a minute and use very high percentage of CPU. If i make request with Chrome or IE, only first request gets stucked.

Everything works fine on IIS 8.5 (no waiting requests when client certificate is required or accepted).

Please help! Any ideas?