[4.3.2]Something changed in cohort webservices?

We have updated from 4.2.2 to 4.3.2 and find this error often in our logs:

[03-Jan-2024 02:10:21 Europe/Amsterdam] REST exception handler: Invalid parameter value detected Debug: cohorts => Invalid parameter value detected: Missing required key in single structure: categorytype
Error code: invalidparameter
* line 362 of /lib/external/classes/external_api.php: invalid_parameter_exception thrown
* line 1483 of /webservice/lib.php: call to core_external\external_api::validate_parameters()
* line 1350 of /webservice/lib.php: call to webservice_base_server->execute()
* line 44 of /webservice/rest/server.php: call to webservice_base_server->run()