MQTTnet using MQTTCloud connection c# Visual Studio

- I need to create connection management between C# FORMs. I have a form to connect and disconnect from MQTTCloud, but when I close this form I am losing connection management in the other FORMs.
- Attached is the code I use in FORM20, to perform the connection and disconnection.
I am using MQTTnet library version 4.3.3.952