The ReadRequest that the server is closing the connection in response to contains 167 items. I’m guessing that you have 167 tags defined for this server and are using an OPC Read Mode tag group as discussed previously.
It’s possible this is too many tags to read at one time from this server. The read for the operation limits is failing with Bad_NodeIdUnknown, so the client is just falling back to default values. A correctly implemented server would be responding with Bad_TooManyOperations in this case, rather than closing the connection, but who knows.
You can try changing the “Max Per Operation” setting on the OPC UA connection to 50 or 100 and see if it helps. You really need to get the vendor of this server involved, though, because it seems to be kind of a poor implementation.