Why does my Azure-deployed web app throw a 'resource not found' error, while it works fine on localhost?

I have 2 apps - let's call them App1 and App2.

Both are Blazor server projects. From App1, we pass through user identity data to authenticate with in App2.

The endpoint in App2 is a component named ExternalAuth accepting 2 parameters:

@page "/externalauth/{EncryptedData}/{EncryptApiKey}"@using FinnivoClients_BlazorServer.Services@inject NavigationManager NavigationManager@inject ExternalAuthService ExternalAuthService@code {    [Parameter] public string EncryptedData { get; set; }    [Parameter] public string EncryptApiKey { get; set; }    protected override async Task OnInitializedAsync()    {        if (string.IsNullOrEmpty(EncryptedData) || string.IsNullOrEmpty(EncryptApiKey))        {            NavigationManager.NavigateTo("/");            return;        }        bool isAuthenticated = await ExternalAuthService.AuthenticateExternalUser(EncryptedData, EncryptApiKey);        if (isAuthenticated)            NavigationManager.NavigateTo("/", forceLoad: true);        else            NavigationManager.NavigateTo("/error");    }}

In App1, it is just a simple button click to redirect to this address:

private async Task RedirectToClientApp(){    // Only encode the values once    string targetUrl = $"https://xxx.azurewebsites.net/externalauth/{encodedData}/{encodedKey}";    // Open the URL in a new tab    NavigationManager.NavigateTo(targetUrl);}

The issue is when we use the live azure link, I get the following error -> The resource you are looking for has been removed, had its name changed, or is temporarily unavailable

When using localhost to test on it works perfectly, example:

private async Task RedirectToClientApp(){    // Only encode the values once    string targetUrl = $"https://localhost:8080/externalauth/{encodedData}/{encodedKey}";    // Open the URL in a new tab    NavigationManager.NavigateTo(targetUrl);}

It even works when I edit take the encoded values and pass it to the localhost link.

What can the cause be, and what can I do to sort this issue?

I tried changing the encoding, and tested various scenarios from taking the last part of the url, and passing it into the localhost link.

Example url - https://xxx.azurewebsites.net/externalauth/oaXpoCd6ymd4bKfLNYd8K5RVnAikn8hU%252BBxkuAXVL9dmN5XFk8tAsHnL9Uir4q6i%252FdUDJb1YwBO6P6de5koJs7mslD0lnwORHACLcneenTfl5eiwENIAsi4hkiA%252Bop20/n3P8LR1PQPkROlih5O1uVRMWaoN4xqo%252BFW41mUUpagS73wExcOhhkgv5uH0FLA9ec