@alexandros-nafas , were you able to figure it out?

@johnmiller It looks like the issue is that the 'retrieve a user via JWT' functionality was removed in 1.60.0. (It appears the User API JWT authentication method was deprecated in version 1.50.0. An issue has been filed to remove it from the client libraries.

Thank you from bringing this to light.

@david-cuen Thanks for the detailed message. I hope to have some time today to try and replicate this. I will let you know what I see.

@simon-chrzanowski can you please share the code you using? (please be sure to hide anything sensitive like your API Key)

@mark-robustelli Thanks, I think that's resolved it!

@Ruka , this seems like something that should be reported as an issue.

This is indeed unusual, especially since the issue appears to affect only a single user and device, which makes a FusionAuth configuration issue unlikely.

A few things to check and try:

Open in External Browser Ask the user to tap the three-dot menu (if available) in the webview and choose “Open in Chrome” or their default browser. If the page loads correctly there, the issue is likely related to the embedded webview rather than FusionAuth itself.

WebView / Browser-Specific Issues

Some Android devices (including certain Xiaomi models) ship with custom WebView implementations or aggressive privacy/security settings that can interfere with embedded web content.

Ensure the device has the latest Android System WebView and browser updates installed.

Domain / CNAME Edge Cases

There have been rare cases where mobile browsers or webviews behave unexpectedly if the domain includes characters such as underscores (_) or dashes (-) in certain positions.

While this typically results in explicit errors (like “Address not found”), it’s still worth reviewing your domain and CNAME setup—especially since you’re self-hosting.

Given that the login works for the same user on other devices, this is most likely a device- or WebView-specific issue rather than a problem with FusionAuth itself. If opening the login page in a full browser works, that should help narrow the root cause to the embedded webview implementation on that device.

You’re correct: FusionAuth’s Lambda environment does not provide access to external libraries (including AWS SDKs or SigV4 helpers), and there is no secure secrets store available to Lambdas. That means if you need AWS SigV4 signing from inside a Lambda, you would have to implement the signing logic yourself and embed any required credentials directly in the Lambda code—this is generally not considered secure.

Also, if you are using FusionAuth Cloud, you cannot place Lambdas into your private network (for example, the same VPC/network as your API Gateway), so that option isn’t available in hosted deployments.

If you need this capability, the recommended approach is typically to move the signing and secret handling into a system you control (for example, a backend service that FusionAuth calls), rather than performing SigV4 signing directly in a FusionAuth Lambda.

Related issue tracking:
https://github.com/fusionauth/fusionauth-issues/issues/1629

This is a known bug, and it looks like the underlying issue has already been identified and fixed. The fix will be included in the next FusionAuth release.

@dalamenona We had the same error with Prometheus.
The following opened FusionAuth issue contains information about the topic

https://github.com/FusionAuth/fusionauth-issues/issues/3082

Best regards.

@dan said in Claims to check when using google as an idp for google workspace:

You should start by checking the relevant google documentation.

As of writing, this is what their doc says:

Using the email, email_verified and hd fields, you can determine if Google hosts and is authoritative for an email address. In the cases where Google is authoritative, the user is known to be the legitimate account owner, and you may skip password or other challenge methods.

Cases where Google is authoritative:

email has a @gmail.com suffix, this is a Gmail account. email_verified is true and hd is set, this is a Google Workspace account.

Users may register for Google Accounts without using Gmail or Google Workspace. When email does not contain a @gmail.com suffix and hd is absent, Google is not authoritative and password or other challenge methods are recommended to verify the user. email_verified can also be true as Google initially verified the user when the Google account was created, however ownership of the third party email account may have since changed.

So in this case, you want to check that hd is set as well as that email_verified is true.

With FusionAuth, you can check this using a reconcile lambda and looking at the id_token:

https://fusionauth.io/docs/extend/code/lambdas/google-reconcile https://fusionauth.io/docs/extend/code/lambdas/openid-connect-response-reconcile

Thank you from bringing this to light.

@patrick_ag Is this just when you are loading the page or are you trying to take some action?