Relation field only allowing one selection

I have a Relation (List of related items) field that is only allowing one selection from the 'related' category.

On previous versions of Flexi, I believe a relation field was to be able to select multiple items by default?

If I select 'Allow multiple values' I am able to select multiple items, but also add another 'set', which is not what I want / need.

Also, the field that displays the item selected is showing as a dropdown field.

Have the settings changed for this field?

Thank you

Joomla ‎5.0.3
Flexi Latest Github release

EDIT: I have another Relation field in a group that does allow multiple selections

hello yes georgios add a new mode for relation field (that can be filtered) but that not compatible with old system, we works on best of 2 ways need some time

I was able to just put it in a field group for now, so at least there is a work around

thanks for return we will work on complet solution without breaking old site

May I add a small comment on this topic?
As already discussed, I believe that this updated version of the field could have advantage
I strongly believe that solution could be to have 2 related fields (the old one and the new one).  I could be wrong, but this is maybe easier than to have more options in the actual one   as the way the field is acting and purpose of this one is slightly different