Hello,
I would like to inform you that the behaviour is by design. The Filter uses a custom cell factory to display the drop-downs.
If you apply your own cell factory after setting the filter, that will disable the filter factory and you won’t get the drop-downs.
The easy way to work around this is to set the filter after setting your custom factory (because the filter factory is smart enough to call your custom factory).
Hope it clarifies.
Regards,
Reema