Azure function app configured invocation blades options loading very slow, unable to change settings.

Question

Azure function app configured invocation blades options loading very slow, unable to change settings.

Muthusamy, Reegan 40

What would be the cause for this? few months back we got the same issue other services. it was identified that, issues with azure backend. cause for the issue still the same? sometimes azure portal behave like this ?

Pravallika KV 16,365 Reputation points Microsoft External Staff Moderator

2026-06-03T17:21:37.4733333+00:00
Hi @Muthusamy, Reegan ,

It sounds like the Function App blade is loading really slowly because the Azure portal UI needs to make a bunch of outbound calls (to your *.azurewebsites.net site, the Kudu site at *.scm.azurewebsites.net, and various Azure Management APIs). If any of those calls are blocked or slow to respond, the portal blades hang or load very slowly.

Here are a few things to check and try:

Open your browser’s F12 Dev Tools → Network tab when you load the Function App blade. Look for calls to <yourapp>.azurewebsites.net, <yourapp>.scm.azurewebsites.net, or management.azure.com. Any failures/delays there point to networking or backend issues.

If you’re running inside an Internal Load-Balanced App Service Environment (ILB ASE) or using Private Endpoints:

Make sure your workstation (or jump box) is on the same VNet.

Confirm your DNS settings (hosts file or DNS server) resolve the *.azurewebsites.net and *.scm.azurewebsites.net names.

Ensure the portal’s function site URL is added to your Function App’s CORS rules.

Verify the SSL certificate chain is trusted by your client.

Check Azure Service Health (in the portal or via CLI) for any ongoing backend or portal incidents that could be impacting performance.

Investigate SNAT port usage: if your App Service plan has exhausted its outbound SNAT ports, calls to backend APIs can hang. You can view SNAT port metrics under your App Service Plan’s Metrics blade.

As a workaround when the portal is unresponsive:

Use Azure CLI or PowerShell to change your Function App settings.

Try a different browser or an incognito/private session to rule out caching/extensions.

Finally, because portal slowness can be transient, try again a little later sometimes the backend slowly recovers on its own.

1 answer

Your answer

Pravallika KV 16,365 Reputation points Microsoft External Staff Moderator

2026-06-03T17:21:37.4733333+00:00

Hi @Muthusamy, Reegan ,

It sounds like the Function App blade is loading really slowly because the Azure portal UI needs to make a bunch of outbound calls (to your *.azurewebsites.net site, the Kudu site at *.scm.azurewebsites.net, and various Azure Management APIs). If any of those calls are blocked or slow to respond, the portal blades hang or load very slowly.

Here are a few things to check and try:

Open your browser’s F12 Dev Tools → Network tab when you load the Function App blade. Look for calls to <yourapp>.azurewebsites.net, <yourapp>.scm.azurewebsites.net, or management.azure.com. Any failures/delays there point to networking or backend issues.

If you’re running inside an Internal Load-Balanced App Service Environment (ILB ASE) or using Private Endpoints:

Make sure your workstation (or jump box) is on the same VNet.

Confirm your DNS settings (hosts file or DNS server) resolve the *.azurewebsites.net and *.scm.azurewebsites.net names.

Ensure the portal’s function site URL is added to your Function App’s CORS rules.

Verify the SSL certificate chain is trusted by your client.

Check Azure Service Health (in the portal or via CLI) for any ongoing backend or portal incidents that could be impacting performance.

Investigate SNAT port usage: if your App Service plan has exhausted its outbound SNAT ports, calls to backend APIs can hang. You can view SNAT port metrics under your App Service Plan’s Metrics blade.

As a workaround when the portal is unresponsive:

Use Azure CLI or PowerShell to change your Function App settings.

Try a different browser or an incognito/private session to rule out caching/extensions.

Finally, because portal slowness can be transient, try again a little later sometimes the backend slowly recovers on its own.

Answer 1

Slow loading or unresponsive blades in the Azure portal for a Function App are typically not caused by the Function App runtime itself but by one of the following:

Platform or service-side issues
- As seen in similar cases, when both the portal experience (blades) and backend operations (like function execution or related services such as Document Intelligence) are slow or timing out, the root cause is often a temporary service-side or regional issue in Azure rather than configuration or code.
- These issues can be region-specific and intermittent, and may not always be clearly surfaced in the error messages.
Configuration or connectivity issues impacting the Function App
Even if the portal UI is what appears slow, underlying Function App problems can cause portal operations (like loading configuration, functions list, or invocation settings) to hang or fail:
- Misconfigured or unreachable storage account (AzureWebJobsStorage) or other critical app settings.
- Network restrictions (VNet integration, NSG rules, firewalls, private endpoints) that block the portal’s calls to the Function App/Kudu endpoints.
- Binding or trigger misconfigurations that prevent the host from initializing correctly.
Code/runtime resource issues causing the host to be unhealthy
- High CPU/memory usage, long-running or stuck functions, or runtime exceptions can lead to an unhealthy script host.
- When the script host is unhealthy or not available, the portal may hang while trying to load functions, invocation details, or configuration.
Daily execution quota or app being stopped/disabled
- If a daily execution quota is configured and exceeded, the Function App is temporarily disabled. This can make some portal controls unavailable or slow/unresponsive until the quota is reset or the next 24‑hour window.
- In this state, the portal can appear partially functional but fail to load or update certain blades.

Because similar behavior was previously traced to Azure backend issues, it is possible that the current behavior is again due to a transient platform or regional problem. However, the exact cause must be verified at the time of the incident.

Recommended checks:

Check Azure Status and Service Health in the Azure portal for incidents affecting the region of the Function App.
Verify that the Function App is healthy and not hitting configuration issues:
- Confirm critical app settings (like AzureWebJobsStorage, FUNCTIONS_WORKER_RUNTIME, and binding-specific settings) are valid and the storage account is reachable.
- Ensure there are no misconfigured network restrictions blocking portal access to the app.
If the app uses a daily execution quota, check whether it has been exceeded and, if so, reset or increase the quota and restart the app.
If the issue persists and no service incident is reported, raise a support request so Azure Support can check for backend or regional issues.

References:

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Azure function app configured invocation blades options loading very slow, unable to change settings.

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