Database Picker and Issue Picker fields configured for "Multiple" selection are not correctly "Required" when set to required via field configuration

Set a Database Picker or an Issue Picker to allow "Multiple" Selection via the below checkbox setting:

If you then configure this field to be required through Field Configuration instead of behaviours, the field will be marked as required with the red asterisk but when the user submits the form it allows the field to be left empty.

Steps to reproduce:

1. Create a Database Picker and an Issue Picker scripted field with the "Multiple" checkbox ticked
2. Add it to the required screens
3. Go to the Field configuration page and set both to required
4. Try to create or edit an issue and leave both fields empty. It will still allow the creation/edit to complete instead of warning the user to fill in fields

Workaround

The workaround is to use behaviours initialiser like this:

getFieldByName("TestDBPickerThree").setRequired(true)