Hi Truong
Thank you for contacting Syncfusion support.
We were unable to understand your query clearly, but we have tried to reproduce the issue using the simple sample. In our sample, we have created the DateTimePickerAdv in design time and dynamically we have created the DateTimePickerAdv, but the calendar had been displayed correctly for both the DateTimePickerAdv. We have also attached the sample and video for your reference. Please download if from the below link:
So kindly check with above solution and let us know whether we followed the correct replication steps to reproduce the issue. If not, kindly modify our sample into issue reproducible along with the brief replication steps. Also let us know your current product version and culture information that you have used in your application. It would be very helpful for us to analyze and provide you the prompt solution at the earliest.
Regards,
Mallika