Updating from Free hosting plan to standard throws 403 forbidden

Recently deployed a static webapp in Azure SWA hosted under free plan and the web app was working fine without any issue. After changing the sku to Standard plan the site throws 403 forbidden.

We changed the hosting plan in Azure portal. Any help is much appreciated. No special config is added `staticwebapp.json` not even routes is part of `staticwebapp.json`

```
{
"trailingSlash": "auto",
"routes": [
{
"route": "/notfound",
"statusCode": 404
}
],
"navigationFallback": {
"rewrite": "index.html",
"exclude": ["/images/*.{png,jpg,gif}", "/css/*"]
},
"responseOverrides": {
"404": {
"rewrite": "/404.html"
}
},
"globalHeaders": {
"content-security-policy": "default-src https: 'unsafe-eval' 'unsafe-inline'; object-src 'none'"
},
"mimeTypes": {
".json": "text/json"
}
}
```