Clicking on a datepicker-cell triggers bootstrap 5 modal closing

[JVT038]

Like the title says.
I have a datepicker inside of a bootstrap modal and when I click on a cell (a year, month, decade), it triggers the modal to close.
For some reason bootstrap thinks the datepicker is outside of the modal, which causes it to close.
Can this be fixed?

[mymth]

I can't reproduce the problem.
https://codepen.io/mymth/pen/dygPNZg

I guess some other program may be doing something like this

document.querySelectorAll('#myModal span').forEach((spanElem) => {
  spanElem.addEventListener('click', () => {
    // ...do something
    //
    myModal.hide();
  });
});