I’m having this same issue as well. Have tried changing return values as well as every method of parsing the date field data in php, but it always either returns empty of with January 01, 1970. The dates are correct in the WP database, so something must be happening on the return trip to the browser.
I am having this same issue on v5.3.2.2.
I have a repeater field composed just of text field rows that is in a group assigned to a page template called Gallery and it will only allow me to delete rows until there is at least one row remaining with at least one character. It’s not a required field, so it seems odd that it’s enforcing what looks like a minimum content requirement.
The final row always reappears with the last entered content on both the front and back end if I try to delete either the content, the row or both – see attached pictures.
This is really unusual to me – I’ve been using ACF for years every day and have never seen this before.