Hi Mohammadreza,
Iam afraid that I was not able to reproduce the issue. Please refer to the following steps that I tried to reproduce it:
1. Drag and drop a ComboBodAdv control to the Form.
2. Set the Items Collection.
3. Right click and select the cut option from the context menu.
4. Paste the same control in the same form and also in different form.
5. Review the Item Collection in the Properties window.
Also I have created a sample to test the issue and it is available in the following link:
http://websamples.syncfusion.com/samples/Tools.Windows/F63706/main.htmHere is the link for the tested video file:
http://www.syncfusion.com/Support/user/uploads/Design_55e7c248.zipPlease have a look at the above sample and if still the issue exists, could you please try reproducing it in the above sample or send us the reproducing steps so that we could sort out the cause of the issue and provide you a solution?
Could you please tell me in which component you are facing this issue?
Kindly let us know if you need any further assistance.
Best Regards,
Jeba.