Content Type missing in actual send graph ql request?

[Xarno]

Version 0.4.6 on Mac

I have a strange behavior with graph ql requests.

When I build this request as normal POST request and omit the content-type header it works. But the generated curl gets a 400 Bad request.
When I add the content-type header in apiark I get a 400 bad request. But then the generated curl is working.

curl -X POST \
  'https://ipx.hamburg-messe.de/graphql/booth' \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer __<my long token>__' \
  -d '{
  "query": "query booth ($expoCode: String!, $filter: BoothQueryFilter, $locale: LocaleType, $offset: Int, $limit: Int, $sortOrder: SortOrder) { booth (expoCode: $expoCode, filter: $filter, locale: $locale, offset: $offset, limit: $limit, sortOrder: $sortOrder) { boothId: boothId regiNo, regiNoHA, standNo, hallObject { id } exhibitorObject { id: corpId slugField: corpName { de_DE en_GB } corpName { de_DE en_GB } corpProfile { de_DE en_GB } image: corpLogo(size: [S72x72, S120x120, S144x144, S240x240]) { url size imageProperties { isDefaultPic } } } } }",
  "variables": {
    "expoCode": "IN26"
  }
}'

Now if I build it as graph ql request I can only ever get the 400 bad request. But the generated code is a correct curl command including the Content-Type header, disregarding if I have it explicitly set or not (but I can see case changes).

Is the „serializer“ for the send request a different one than the one for the „code display“?