Hiden columns are displayed after reload

[ollily]

Hello,

according to #373 there might be another problem / error with Release ChanSort 2023-10-22. The columns which are hidden by me, will not stay hidden, when the same channel set is reloaded or another channel set is loaded.

Pre Requirements

• Start the application
• Switch off "Hide/unhide columns automatically"
• Optionally ignore the .NET-Exception (#373)
• Load a channel set
• Choose option "Modify current list"

Reproduce Error

• "Hide a column", the column is arbitrary, e.g. "Service Type"
• Click on "Reload"

=> Every hidden column is visible again

Expectation

I expected that the hidden columns will stay hidden, at least during one opened instance of the application. If the column settings is stored when exiting the application and loaded at startup can be a feature request.

Best regards, Oliver