a composite label value is not updated when the child topic involved in it is

[Malte]

What i justhave observed is, when updating the "ka2.geo_object.name" value via a PUT to the "core/topic" REST API, the label of the "Geo Object" does not change.

I could not find a related ticket dealing with this.

My first guess is, may be the following has a role in this issue:
Some type defs do not include an explicit label configuration, such as "ka2.geo_object" for example. In this case, some default applies to calculate the label value used in the composite topic (the rule is something like, "first text child" or so but i am not 100% sure).

[jri]

When updating a child topic directly the parent's label is not recalculated. You have to update the parent instead.

Instead

PUT /core/topic/<childId>

{
    value: "new value"
}

do this:

PUT /core/topic/<parentId>

{
    childs: {
        ka2.geo_object.name: "new value"
    }
}

[jri]

Regarding the label config you're almost right. If there is no explicit label config for a composite the label of its first child is used, regardless of its data type (Text, Number, ...). This rule applies recursively.