Why does MS Access reload after selecting a date in a field?

Question

Visual Basic

The essence of the code is that after updating the date in the "Execution Date" field of the "Custom IP Order Card" form, only those journalists who are free from writing IP * will be shown in the next combo box of this form. The period when a journalist is busy writing IP lies between the "StartDate" and "EndDate" fields of the "Approved Topics" table. And if "ExecutionDate" > "EndDate", then the names of the journalists in the combo box "JournalistID" (on the form it is "JournalistName") appear on the form. It is worth noting that I throw the codes and names of journalists that satisfy the condition into the clipboard (the table that is cleared and re-created when the due date is selected), which is the source of the rows of the combo box.
But the file is restarted due to the termination of its work. There are only assumptions that there are problems either in the Access program itself, or in my file (it is possible that because of the code).
*IP - information product
*IA - information agent

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