Modal-container pop-up problem

The modal-container code from dash recipes i had integrated in my new app. Until last weekend it was working fine, but from last 3 days the popup is not being displayed, only a black screen appears.
Even the code shared on dash recipes we tried to run and faced the same problem.
Is it because of any updates in dash or core components or html components. Also does the className affect the working or is it being updated.
Please help with this, as I m not able to figure it out !!!