Replied 30 July 2020, 7:36 pm EST
Sorry, I must have missed this. Unfortunately, there is no solution for this issue. There is only one solution for your main issue that is to iterate over each value and convert it from string to date manually. The previous solution also does the same but it converts string to date for the visible data only so that the performance is not affected. But since, there are still some data left which have not been converted, they will be displayed on the filter editor.
So, ultimately, you will have to iterate over each data for conversion. You can also add a spinner (refer to the link at the bottom) while converting the data so that the user will think the data is still being loaded.
Sorry for the inconvenience caused.