I have been trying to create collections to organize my catalog items, but it appears that the collections feature is not functioning as expected. other community posts facing same issue:

https://developers.facebook.com/community/threads/430022226558492/?join_id=f8625f32d5ceb3f7d

https://developers.facebook.com/community/threads/1104416270863922/?join_id=f94e298b680f25352

https://developers.facebook.com/community/threads/222137454323396/?join_id=f03fb76ef0ee81fb7

https://developers.facebook.com/community/threads/1202862247527971/?join_id=f1446a6c8cfc502b8

this issue seems to be abandoned and forgotten, despite being crucial.