You are trying to drag and drop elements inside Cloud for Customer Extended App using an Apple Pencil or Mouse, however this is not working.
SAP Cloud for Customer
Apple Pencil and Mouse are not supported for this functionality.
An alternative option may be to check the SAP Cloud for Customer Customer Influence to submit an idea:
Apple Pencil, IPad, Drag and Drop, Mouse , KBA , AP-RC-MOB-IPD , SAP Hybris Cloud for Customer Extended App on iOS , Product Enhancement