Second very slow variable subscription - by: phil56

Hi ! We work with librairies Quick OPC-UA 2018.3.
When we start the program, we subscribe to 2724 variables in 14 seconds :

PlcClient : subscribe event
PlcClient : open
PlcClient : subscribe data change
PlcClient : subscribe variable ns=2;i=3006287402(23/09/2019 15:24:13:1)
PlcClient : subscribe variable ns=2;i=2438195688(23/09/2019 15:24:13:2)
...
PlcClient : subscribe variable ns=2;i=3444163552(23/09/2019 15:24:27:2723)
PlcClient : subscribe variable ns=2;i=3632956119(23/09/2019 15:24:27:2724)
PlcClient : end

Then, if the program detects a connection's error, we close / open the connection.
We subscribe again to 2724 variables but in 5 minutes:

PlcClient : subscribe event
PlcClient : open
PlcClient : subscribe data change
PlcClient : subscribe variable ns=2;i=3006287402(23/09/2019 15:26:54:1)
PlcClient : subscribe variable ns=2;i=2438195688(23/09/2019 15:26:54:2)
....
PlcClient : subscribe variable ns=2;i=3444163552(23/09/2019 15:32:32:2723)
PlcClient : subscribe variable ns=2;i=3632956119(23/09/2019 15:32:32:2724)

This is the code implemented to close the connection :

And this is the code implemented to subscribe :


Can you help me about this ?