Is MultiSelect Dropdown working on Adalo 2.0?

I am building an app with Adalo 2.0.
My service is a closed social network and I am trying to create a feature to tag friends in posts.

I used MultiSelect Dropdown to select multiple friends to tag, but it doesn’t seem to be working.

I used the Normal Dropdown Menu to try and it successfully added one friend. Therefore, there appears to be no problem with the database linkage.

Does anyone have a solution to select multiple friends?
Thanks.