Open the form you set wrong again.

Select the field where you set the error.

Then click on the field below the table tool above.

In the data type, you can see that the format set before is short text, but the type of birthday should be date and time.

Click the inverted triangle icon at the back to select the time and type.

That's enough. Enter the time, and there will be no display type error. In addition, you can format the field size or data type.