初始化用户表单时未填充Combobox，但在关闭并重新打开表单后填充

For some odd reason, my combo boxes are not "preloaded" with content once the form is initialised, the user has to first close down the form and then open it again for the combo boxes to be prefilled. It's a bug that is starting to irritate the end user, any idea why would this happen? I've attached For some odd reason, my combo boxes are not "pr