Google Places CORS Error, serving Flutter Web, Even When Redirecting with NGROK --host-header-rewrite flag?

Question

StackOverflow Community,

I have a problem that someone may have solved before, but I find it truly confounding.I'm running a flutter web server on a vm in Azure with

flutter run --release -d web-server --web-port 8081

After getting CORS error attempting to hit Maps or Places API, I elected to run another instance of NGROK with the --host-header=rewrite flag, as I have done for other APIs to avoid this CORS error. This works fine with all of the other APIs we are hitting.

However, when serving this app, I still get a very similar CORS error, identifying items hidden:

Access to XMLHttpRequest at 'https://hidden1.ngrok.io/maps/api/place/autocomplete/json?input=s&key=hidden&sessiontoken=hidden' from origin 'https://hidden2.ngrok.io' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.Hidden1 is my maps API redirect and Hidden2 is my app's dev redirect.

Am I still getting this error because I somehow need to serve place autocomplete, in this case, from the same subdomain as the app's subdomain?? I'm confused, because this is not a constraint of any other APIs I remember using in the past.

I still get a 200 response with this CORS error, but chrome refuses to do anything with it unless I use a CORS-enabling extension.

If I do need to redirect Places and the app's Web Server through the same URL, are there any recommendations for doing this?

Thanks in advance for your time and thoughts..