POST requests against Red Hat Satellite do not get accepted

Issue

• The response of POST requests against the Satellite API is HTTP/1.1 406 Not Acceptable

  $ sudo curl -v --header "Accept:application/json,version=2" --header "Content-Type:application/json" --request POST --user user:password --insecure https://satellite.example.com/api/hosts/136/play_roles 
  *   Trying 10.xx.xx.xx...
  [...Output omitted...]
  * Server auth using Basic with user 'user'
  > POST /api/hosts/136/play_roles HTTP/1.1
  > Host: satellite.example.com
  > Authorization: Basic XXXXXXXXXX==
  > User-Agent: curl/7.61.1
  > Accept:application/json,version=2
  > Content-Type:application/json
  > 
  < HTTP/1.1 406 Not Acceptable
  < Date: Mon, 15 Mar 2021 09:05:03 GMT
  < Server: Apache
  < X-Request-Id: 9a8d10a5-a4f0-4b85-94c9-d19ab2fcd419
  < X-Runtime: 0.021994
  < Strict-Transport-Security: max-age=631139040; includeSubdomains
  < X-Frame-Options: sameorigin
  < X-Content-Type-Options: nosniff
  < X-XSS-Protection: 1; mode=block
  < X-Download-Options: noopen
  < X-Permitted-Cross-Domain-Policies: none
  < Content-Security-Policy: default-src 'self'; child-src 'self'; connect-src 'self' ws: wss:; img-src 'self' data:; script-src 'unsafe-eval' 'unsafe-inline' 'self'; style-src 'unsafe-inline' 'self'
  < X-Powered-By: Phusion Passenger 4.0.18
  < Content-Length: 0
  < Status: 406 Not Acceptable
  < Content-Type: text/html; charset=utf-8
  <
  * Connection #0 to host satellite.example.com left intact