Device API does not update coordinates or location_manual (Observium 24.6.13582)

I'm using Observium 24.6.13582 (stable) and believe I've found an issue with the device update API.
According to the API documentation, coordinates and location_manual can be updated using the "Changing a device" endpoint.
However, while updates to other fields work correctly, these two fields do not.
For example, this request works as expected:
 
{{curl -u user:password \
 -X PUT http://observium/api/v0/devices/47/ \
 -H "Content-Type: application/json" \
 -d '{"disabled":"1"}'}}
But these requests do not update the device and return HTTP 304 Not Modified:
 
{{curl -u user:password \
 -X PUT http://observium/api/v0/devices/47/ \
 -H "Content-Type: application/json" \
 -d '{"coordinates":"51.509865,-0.118092"}'}}
 
{{{}curl -u user:password \
 -X PUT http://observium/api/v0/devices/47/ \
 -H "Content-Type: application/json" \
 -d '{"location_manual":"{}}}1","coordinates":"51.509865,-0.118092"}'
I've verified that: * Authentication is working.

• The endpoint and HTTP method are correct.
• Other fields (e.g. disabled) update successfully
• 
  Could you please confirm whether coordinates and location_manual are supported for updates in Observium 24.6.13582, or whether this is a bug or documentation issue?