Vue3 , version 3.0.0-beta.2, Slot with Group and searchable is not working

[wongyat88]

vue-multiselect version 3.0.0-beta.2

Reproduction Link

Code

Steps to reproduce

The backend data is like:
[{
"barcode": "rm-00034",
"rfidCode": "rm-00034",
"desc": "rm-00034",
"imageUrl": "http://xxx.xx.x.x/media/uploads/items/no_image.jpg?20230626170259919162",
"itemName": "Stone Name 34",
"itemDesc": null,
............
"mainMaterialSubCategoryID": "8"
},s
........ around 1000+
]

Expected behaviour

1. I tried to add groups into it, but seem it not working with slot. The group label can be show with $groupLabel, but the groupLabel still able to select, i tried to hardcode isDisable = True in options but same, still able to select the option.
2. The searchable function is not working, It cannot search, i tried barcode, desc, name and other column, none of them searchable. I follow the example, the example work a bit only. For example, the desc in the example is 'Discovering new species!', i enter 'new', it also cannot search. It only return result if i enter 'Disco'.