Hi Sandipan,
Thanks for your interest in Syncfusion products.
We are not able to reproduce the issue when we set the MDILayout to the DockingManager. It automatically fires the Focus event of the child windows. We have attached the sample here whilch will illustrate this.If you feel still the issue persists could you please modify the sample and send it to us. It would be helpful to find an accurate solution.
Please let us know if you have any queries.
Regards,
David C
DockingManagerSample_b198cbc6.zip