Could you perform a reset of your game settings?
1. Close all game clients
2. DIsable all addons, you can rename the Interface directory, in-game directory if you have it
3. Open launcher settings, and on the last tab click "Reset Settings"
4. Launch the game, open the prestige window, uncheck the checkbox, click save near minimap, close the game client, and check if the Prestige window appears on the game restart and the zone change.
This way, we will eliminate add-ons conflict, and settings, which later can be restored.