Printer Driver Mapping and Compatibility Policy are not being applied to users.
Solution for Scenario 1: The "Print Driver Mapping and Compatibility" printing policy is only for auto-created printers it cannot be used for session or auto-connected network printers. This is as designed.
Solution for Scenario 2: If you are auto-creating user printers but have the "Driver Policy Settings" Policy set to "Use Universal Printing Only" option, this will override the "Print Driver Mapping and Compatibility" policy and auto-create all user printers with a Citrix Universal Driver. If you want to use a Citrix Universal Driver and vendor or model specific drivers, you need to set the "Driver Policy Settings" to not configured or set it to "Use Universal Printing only if requested driver is unavailable" which is the default behavior.
Citrix Documentation - Client Printers policy settings
Citrix Documentation - Mapping Client Printer Drivers
Citrix Documentation - Drivers policy settings > Universal print driver usage