Microsoft Teams App Not Loading After Deployment in Kubernetes, but Logs Show in Console

I have built a custom Microsoft Teams app using TypeScript React and deployed it inside a Kubernetes (K8s) pod. When I upload the manifest to Microsoft Teams, I don't see the app in the UI. However, when I inspect the console logs (F12 in Teams), I can see logs coming from the app, meaning it is loading in the background.

When i run the app locally everything works fine.

Manifest.json

{

  "$schema": "https://developer.microsoft.com/en-us/json-schemas/teams/v1.19/MicrosoftTeams.schema.json",

  "manifestVersion": "1.19",

  "version": "1.2.0",

  "id": "32e8e5ff-cfee-4782-a059-7e0ed215a3a4",

  "developer": {

    "name": "ExampleB.V",

    "websiteUrl": "https://example.com/",

    "privacyUrl": "https://example.com/privacy-statement/",

    "termsOfUseUrl": "https://example.com/privacy-statement/"

  },

  "staticTabs": [

    {

      "entityId": "index",

      "name": "Home",

      "contentUrl": "https://example.com/index.html#/tab",

      "websiteUrl": "https://example.com/index.html#/tab",

      "scopes": ["personal", "groupChat", "team"]

    }

  ],

  "validDomains": [

    "*.example.com",

    

  ],

  "webApplicationInfo": {

    "id": "32e8e5ff-cfee-4782-a059-7e0ed215a3a4",

    "resource": "api://example.com/32e8e5ff-cfee-4782-a059-7e0ed215a3a4"

  }

}

What I Have Tried:

✅ Checked logs in Teams Console (F12)

• Logs from the app are visible, but the UI doesn’t appear.

✅ Verified HTTPS Access

• When I open https://example.com/index.html#/tab in a browser, the app loads fine.

✅ Added Domain to validDomains

• example.com is already listed.

✅ Checked for CSP Errors (F12 in Teams Console)

• No explicit CSP errors, but I'm not sure if it's blocked due to iframe restrictions.

✅ Checked Kubernetes Deployment & Service

• The pod is running correctly, and logs show that requests are reaching the server.

Possible Issues & Questions:

1. Is Microsoft Teams blocking my app due to iframe security policies?
   • Do I need to explicitly allow https://teams.microsoft.com in my Content-Security-Policy headers?
2. Is my Kubernetes ingress configuration missing something?
   • How can I confirm that the service is properly routing traffic inside Kubernetes?
3. Is there an issue with webApplicationInfo.resource?
   • Does this value affect the app's visibility in Teams?
4. Are there any specific Teams permissions required for rendering static tabs?