Teams App Error After 60 Seconds: "There was a problem reaching this app"

Problem

My Teams tab app loads and works perfectly fine, but after exactly ~60 seconds, it shows this error screen:

"There was a problem reaching this app" with a Retry button

(Screenshot attached)

Setup

• Teams Personal & Meeting tabs
• Node.js backend on Azure
• Azure AD authentication
• Multi-tenant app

What I've Checked

• ✅ No errors in browser console
• ✅ No errors in server logs
• ✅ All API calls complete successfully
• ✅ Teams SDK initializes without errors
• ✅ Authentication tokens are valid
• ✅ App works fine locally - only happens in production

The Strange Part

The app functions normally during those 60 seconds. Everything loads, authentication works, API calls succeed. Then suddenly this error appears.

The 60-second timing seems too consistent to be coincidental - suggests some kind of timeout.

Question

Has anyone seen this before? Is there a Teams SDK timeout or callback I'm missing? Should I be calling some kind of notifySuccess() or similar after initialization?

Any suggestions on what could cause a delayed error like this would be appreciated!