Hi Chanokthorn! Thanks for posting in the Community. It looks like you might have a Conditional Formatting rule adding the cross icon to your shapes. You can check your Conditional Formatting rules by selecting the wand icon in the toolbar above your canvas. This will bring up all your Conditional Formatting rules. From here you can choose to unapply or delete any rules which might be adding the cross to your shape. For more information please see our Conditional Formatting and Icon Sets article from the Lucid Help Centre. 

Let me know if you're not able to find a Conditional Formatting rule causing the issue or if you have any questions. Hope this helps!