In 8.10.x the HttpClient component appears to not complete the full NTLM handshake while executing an HttpRequest. The HttpResponse message is 401 Unauthorized, but what should happen is that additional back and forth messages should be sent in the background in order to successfully receive a 200 status code.
The last working version is 18.104.22.168. Making no other change beyond updating to any version of 8.10.x.x will cause the 401 Unauthorized error and the workaround is to downgrade back to 22.214.171.124.
This forum post describes the issue and indicates downgrading to 126.96.36.199 solves the issue for several people:
*** This bug has been marked as a duplicate of bug 30869 ***