Auto reconnect Blazor Serverside

<script>
    // Wait until a 'reload' button appears
    new MutationObserver((mutations, observer) => {
        if (document.querySelector('#components-reconnect-modal h5 a')) {
            // Now every 10 seconds, see if the server appears to be back, and if so, reload
            async function attemptReload() {
                await fetch(''); // Check the server really is back
                location.reload();
            }
            observer.disconnect();
            attemptReload();
            setInterval(attemptReload, 10000);
        }
    }).observe(document.body, { childList: true, subtree: true });
</script>

This will wait until the reload button appears and then will wait until the server is back up before actually reloading.

From https://github.com/dotnet/aspnetcore/issues/10325#issuecomment-537979717

You can try this code:

<script src="_framework/blazor.server.js"></script>

<script>
   Blazor.defaultReconnectionHandler._reconnectCallback = function(d) {
        document.location.reload(); 
   }
</script>