Forms in modal dialogs are not locked when submitted

Steps to reproduce in Zabbix 6.0:

1. Navigate to Monitoring -> Services;
2. Switch to edit mode;
3. Press "Create service" to open modal dialog with service creation form;
4. Put the mouse pointer caret into some input text field and press enter on your keyboard. Don't release the key.

Result:

Form is not frozen after first submit and multiple error message boxes are added at the top.