Hi @krishnags,
Could you please share a bit more about your data source? Is it a SP list?
Do you mean that the Custom Date type column could not be displayed within your canvas app?
Have you taken a try to refresh your data source manually within your app?
I have made a test on my side, and don't have the issue that you mentioned.
Please consider take a try to refresh your SP list data source manually within your canvas app, then check if the custom Date column has been displayed within your app:
In addition, please consider take a try to re-create a canvas app based on your SP list data source (or other data source), then check if the issue is solved.
Best regards,