OPCUA server stops working randomically

Hi,

I currently have connected multiple machines (sinumerik 840D) with an OPCUA reader (Kepware Server EX 6) which I use to read telemetry data live.

I'm currently facing an issue on multiple machines, which at some point in time just stop sending data, and can't connect via the OPCUA protocol.

If I go on the machine and open Network -> Opcua -> Status I get:

- Server status: Not connection possible  (I have the italian language, translation might be different)

- Connected clients: FindServers:CB:bas status (0x80050000)

The only way to fix the error is to:

1) go to the licenses page and disable the OPCUA

2) restart the machine

3) go to the licenses page and enable the OPCUA

4) restart again

But of course restarting machines in plant isn't always easy and I'm currently looking for a solution that avoid disconnections and data losses altogether...

As I said this problem occurs on different machines...

Thank you in advance to anyone who can help