Updated the Codesys Safety SIL2 package from v3.5.18.1 to v3.5.22.10 Codesys Version 64 3.5.18.0 After the update the assignment of variables from different VarGlobal lists was unstable. Selecting one group could cause another group to be deselected after code generation. I was unable to perform a compilation were all variables maintained the selection after code generation. Rolled back to the older version and the issue seem to be mostly solved.