Instance is not woken up by Function Proxy (keeps returning 503)

[This setup](https://github.com/scale-tone/cognitive-search-static-web-apps-sample-ui#cognitive-search-static-web-apps-sample) now suffers from Web App instance going to (some sort of) sleep and then not being properly woken up.

Specifically, when you navigate to https://lively-sand-033e9ec03.azurestaticapps.net/ after a period of inactivity, the statics are being fetched from either browser cache or CDN (and therefore do not wake up the instance), while /api requests keep failing with 503 status for quite a while (minutes):


The specifics of /api endpoint in that app is that it doesn't have any Functions, [only Proxies](https://github.com/scale-tone/cognitive-search-static-web-apps-sample-ui/blob/master/api/proxies.json). I'm speculating here, but this might be the reason why the instance is not being properly woken up.

**To Reproduce**

Go to https://lively-sand-033e9ec03.azurestaticapps.net/ in the middle of the night and press F12. Observe the Network tab.

Code is here: https://github.com/scale-tone/cognitive-search-static-web-apps-sample-ui

**Expected behavior**
Requests to /api endpoint should never fail. If the instance is asleep, they should bring it back online and return success.