The 101 (Switching Protocols) status code indicates that the server understands and is willing to comply with the client's request, via the Upgrade header field (Section 6.7 of [RFC7230]), for a change in the application protocol being used on this connection.
I read this as the Server is to return 101 to the client ( LabVIEW ) if the Upgrade header field in the request.
Are you including an Upgrade header option in your request?
Are you receiving a 426 code?
The Server should return code 426 ( which includes an upgrade header field) if the requested protocol is refused.
6.5.15. 426 Upgrade Required
The 426 (Upgrade Required) status code indicates that the server refuses to perform the request using the current protocol but might be willing to do so after the client upgrades to a different protocol. The server MUST send an Upgrade header field in a 426 response to indicate the required protocol(s) (Section 6.7 of [RFC7230]).