Referencing custom fields date in forms?

I am adding dynamic data to my form, but I have a problem with the following.

I want to display start and end date from custom fields, and if the user is not ok with them, he should add his own dates. I did it in two ways.

First – referencing dates inside a text field. That works, but the user can delete that text, which is not really what I want. I want the text field to be undeletable.

Second – referencing the date inside date chooser field – this is exactly how I would like it, but unfortunately date displayed is not referenced correctly, it’s displayed as 01/01/2021.

Any way to solve this?