Updating a WMS cascading Layer via REST API causes 500

[khercouet]

Context

I am working with GeoServer 2.27.2.0 (cloud) and the REST API.
I want to create a workspace, a WMS store, a WMS layer, and then update the WMS layer title.

Observed Behavior

Endpoint /workspaces/{workspace}/wmsstores/{store}/wmslayers/{layer}
returns 500 with exception (see attached exception file)

wmslayers rest doc
Endpoint /workspaces/{workspace}/wmslayers/{layer}
returns 200 OK but actual update happens, logs still show errors.

Test with different open source data :

• https://wms.geo.admin.ch/?SERVICE=WMS&REQUEST=GetCapabilities&VERSION=1.3.0
• https://data.geopf.fr/wms-r/wms?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities

Expected Behavior

Both endpoints should allow updating the WMS layer (e.g., title) without error

Steps to reproduce issue

1. Create a workspace in GeoServer UI

• Name: myworkspace
• Namespace URI: myworkspace

2. Create the WMS store

curl -i -X POST "http://localhost:9090/geoserver/cloud/rest/workspaces/myworkspace/wmsstores" \
  -u admin:geoserver \
  -H "Content-Type: application/json" \
  -d '{
    "wmsStore": {
      "name": "mystore",
      "capabilitiesURL": "https://wms.geo.admin.ch/?SERVICE=WMS&REQUEST=GetCapabilities&VERSION=1.3.0"
    }
  }'

3. Create the WMS layer

curl -i -X POST "http://localhost:9090/geoserver/cloud/rest/workspaces/myworkspace/wmsstores/mystore/wmslayers/" \
  -u admin:geoserver \
  -H "Content-Type: application/json" \
  -d '{
    "wmsLayer": {
      "name": "mylayer",
      "nativeName": "ch.bakom.notruf-147_mobilnetz",
      "title": "mytitle"
    }
  }'

4. Update the WMS layer (first endpoint)

curl -i -X PUT "http://localhost:9090/geoserver/cloud/rest/workspaces/myworkspace/wmsstores/mystore/wmslayers/mylayer" \
  -u admin:geoserver \
  -H "Content-Type: application/json" \
  -d '{
    "wmsLayer": {
      "title": "mynewtitle"
    }
  }'

see log log.txt