We were running hyperv 2012 r2 core. Over the weekend we have reinstalled and reconfifured these servers with hyperv core 2016 and 1 hyperv 2019 server, the 2016 std server, works 100% the system communicates with it and can provision etc, however where we were able to connect to our other hyperv servers using the remote option, this no longer seems to work with 2016.  we keep getting the error

Unable to connect to Hyper-V server

Possible reasons:

1. You are going to manage remote Hyper-V server (either Server Core or Hyper-V Server 2008 machine) where SolidCP Server is not installed. Type the correct server name at the top of this form and then click "Connect" button.
2. SolidCP Server has insufficient permissions to connect remote Hyper-V server. Please refer administrator guide for client and server setup instructions.
3. Lost connectivity with SolidCP Server installed on Hyper-V virtualization server. Check connectivity and open service properties page once again.

However hyperv manager is also installed on this server and can migrate and replicate across all the servers, we need help identifying why this would be like this when it worked before..