I have been months desperate struggling to figure out the issues with google cast integration and its feature “cast.show_lovelace_view”. Starting last autumn little by little I lost history data when casting my lovelace views to google nest hub. I think this year loading history data stopped totally - until today after loading the latest OS 5.12.
Now everything works like charm! Who ever did what ever he/she did you deserve a large medal for this update. You really made my day!