Seems like manual changing of the "special" column in directus_fields table for the given field solves the problem. But still its scary when the "type" of column changed without user permission and user can't revert it from admin panel.

@slyk what database are you using?

@rijkvanzanten I could reproduce this with SQLite

Ah, that confirms my suspicion. I was assuming this would be the case for the database types where there is no native UUID, as it has to use a char(36) instead. The data model change update to remove the uuid generating flag then in turn causes the api to think it's just a regular string instead.

@slyk what database are you using?

Yes its mysql or mariadb.
Yes the field by itself is varchar(36) in database. So in my post is sometimes put "type" in quotes, so its not really a type.

And string is great sometimes. I could have uuids for simple items and some predefined ids for system standard items like "notfound" id for all the times that the item was searched and not found I have this "dummy" object instead of null.

I just want uuid generator to work as needed when we need it :) and if possible put manual string when i need it (but that looks more like feature request not a bug) :)

In the meantime, as an alternative to manually modifying the database, you can update the field via API ¹ with the following payload:

{
  "meta": {
    "special": ["uuid"]
  }
}