document type editor: node names of created fields get the type name, not the path name

In the document type editor (Documents perpective / Configuration tab) I create fields on a document type, name the path of the fields, click Done and Commit. When I take a look at the created nodes in the console, the hipposysedit:field nodes have the name of the type (string, text, hippo_mirror) and not the name of the path (ns:title etc). See the stacktrace for a clue to the problem. When I create another string field I get the error that a node with name 'string' already exist.

Project versions:
<parent>
<groupId>org.onehippo.cms7</groupId>
<artifactId>hippo-cms7-release</artifactId>
<version>7.7.0</version>
</parent>

<hippo.repository.version>2.22.02</hippo.repository.version>
<hippo.cms.version>2.22.01</hippo.cms.version>
<hippo.hst.version>2.24.02</hippo.hst.version>
<hippo.packages.version>2.22.01</hippo.packages.version>