Problem with exposing an entity reference field as filter with checkboxes

Hello.
I have an entity reference field in a content type and I'm trying to set up a view's exposed filter for this field where I want the option to be displayed as checkboxes instead of a text field.
I've already checked that the option Render Views filters as select list is selected on the configuration of the field but i receive the notice The selected behavior handler is broken, as shown on the attached screenshot.
When configuring the view, when I add this field as an exposed filter I see no 'Is one of' option and the Checkboxes option is not available on the display settings of BEF.
The number of entities/options of the referenced content type is less than 20 so I assume that it's not an out of memory error.
Does anyone have the same problem?