STACKIT Provider : Failing to create MongoDB Flex Instance

[saurabh2590]

Description

• We are using STACKIT Terraform provider version 0.115.0.
• When we run terraform apply to create the mongodb flex instance we simply get 404 error with the message
  Calling API: 404 Not Found, status code 404, Body: {"message":"mongodb not │ found","code":404,"type":"NotFound"}
• We also tried with version 0.114.0 and we received the same error message as above.

Steps to reproduce

• Simply declare the MongoDB Flex instance in the terrafor code to create a new MongoFlex instance.

resource "stackit_mongodbflex_instance" "example" {
  project_id = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
  name       = "example-instance"
  acl        = ["0.0.0.0/0"]
  flavor = {
    cpu = 1
    ram = 4
  }
  replicas = 1
  storage = {
    class = "premium-perf2-mongodb"
    size  = 10
  }
  version = "7.0"
  options = {
    type                       = "Single"
    snapshot_retention_days    = 3
    point_in_time_window_hours = 30
  }
  backup_schedule = "0 0 * * *"
}

1. Run terraform apply
2. It produces the issue.

 with stackit_mongodbflex_instance.mongodb-cluster (mongodb-cluster),
│   on cdk.tf.json line 132, in resource.stackit_mongodbflex_instance.mongodb-cluster (mongodb-cluster):
│  132:       }
│ 
│ Calling API: 404 Not Found, status code 404, Body: {"message":"mongodb not
│ found","code":404,"type":"NotFound"}
│ 
│ 
│ Trace ID: "8eb72ba607dc14ea50e36e259d23936c"

Actual behavior

• The STACKIT API is returning 404 even for the API calls.

Expected behaviour

• The stack creation should simply succeed with creation of MongoDB flex instance.

Environment

• OS: MacOS/Linux
• Terraform version (see terraform --version): v1.15.2
• Version of the STACKIT Terraform provider: v0.115.0 & v.114.0 as well

Additional information

• It worked perfectly fine until this Wednesday.

[saurabh2590]

Please also see audit log entry. Maybe it has a hint that an old route is being called.

{
  "_source": {
    "@timestamp": "2026-09-18T09:13:02.212Z",
    "attributes": {
      "client.address": "127.0.0.6",
      "cloud.provider": "stackit",
      "cloud.region": "eu01",
      "email": "operations-48qejt1@sa.stackit.cloud",
      "http.request.method": "POST",
      "http.response.status_code": 404,
      "service.instance.id": "00000000-0000-0000-0000-000000000000",
      "service.name": "mongodb",
      "stackit.action": "mongodb.instances.create",
      "stackit.initiator": "75d6c251-de17-4748-af5c-03b7d0a80a58",
      "stackit.initiator.email": "operations-48qejt1@sa.stackit.cloud",
      "stackit.log.id": "3c422121-78e0-4b37-baf9-23abcdea0dab",
      "stackit.log.type": "AUDIT",
      "stackit.project": "ci01",
      "stackit.request.body": "{\"acl\":{\"items\":[\"192.214.177.105/32\",\"45.141.75.168/32\",\"192.214.164.96/32\",\"45.141.74.102/32\"]},\"backupSchedule\":\"0 0 * * *\",\"flavorId\":\"2.8\",\"name\":\"ci01-mongodb-cluster-application\",\"options\":{\"type\":\"Replica\"},\"replicas\":3,\"storage\":{\"class\":\"premium-perf6-mongodb\",\"size\":1500},\"version\":\"7.0\"}\n",
      "stackit.resource.id": "06fbfdee-dcda-440a-b3b7-7e2ee2feda39",
      "stackit.resource.type": "PROJECT",
      "stackit.visibility": "PUBLIC",
      "url.path": "/v1/projects/06fbfdee-dcda-440a-b3b7-7e2ee2feda39/regions/eu01/instances",
      "user_agent.original": "stackit-terraform-provider/0.113.0"
    },
    "body": {
      "text": "RequestReceived create service instances"
    },

[saurabh2590]

It seems that the bug is not in the terraform provider but more at the API level as we can reproduce the bug also on the portal.