[GNC] www.alphavantage.co suffering currency conversion failure from Gold (XAU) & Silver (XAG) to any resulting currency other than USD since the 14th Aug

[gnucash @ oijn]

Seems that www.alphavantage.co has suffered a regression regarding 
currency conversion from from Gold (XAU) & Silver (XAG) to any resulting 
currency other than USD since approx. the 14th Aug.

This has worked for the last 8+ months and the last successful lookup 
transaction for me was on the 14th Aug.  It has failed every lookup 
since.

===============================
Failure Example 1  XAU into GBP

Request:
   
https://www.alphavantage.co/query?function=CURRENCY_EXCHANGE_RATE&from_currency=XAU&to_currency=GBP&apikey=MK...>8

Reply:
{
     "Error Message": "Invalid API call. Please retry or visit the 
documentation (https://www.alphavantage.co/documentation/) for 
CURRENCY_EXCHANGE_RATE."
}

===============================
Failure Example 2  XAG into GBP

https://www.alphavantage.co/query?function=CURRENCY_EXCHANGE_RATE&from_currency=XAG&to_currency=GBP&apikey=MK...>8

Reply:
{
     "Error Message": "Invalid API call. Please retry or visit the 
documentation (https://www.alphavantage.co/documentation/) for 
CURRENCY_EXCHANGE_RATE."
}

===============================
Success Example (only one I can get to work)  XAU into USD

Request:
https://www.alphavantage.co/query?function=CURRENCY_EXCHANGE_RATE&from_currency=XAU&to_currency=USD&apikey=MK...>8

Reply:
{
     "Realtime Currency Exchange Rate": {
         "1. From_Currency Code": "XAU",
         "2. From_Currency Name": "Gold Ounce",
         "3. To_Currency Code": "USD",
         "4. To_Currency Name": "United States Dollar",
         "5. Exchange Rate": "1512.49000000",
         "6. Last Refreshed": "2019-08-17 14:55:33",
         "7. Time Zone": "UTC",
         "8. Bid Price": "-",
         "9. Ask Price": "-"
     }
}

===============================
Standard Currency Conversions work - example USD into GBP

Request:
https://www.alphavantage.co/query?function=CURRENCY_EXCHANGE_RATE&from_currency=USD&to_currency=GBP&apikey=MK...>8

Reply:
{
     "Realtime Currency Exchange Rate": {
         "1. From_Currency Code": "USD",
         "2. From_Currency Name": "United States Dollar",
         "3. To_Currency Code": "GBP",
         "4. To_Currency Name": "British Pound Sterling",
         "5. Exchange Rate": "0.82290000",
         "6. Last Refreshed": "2019-08-17 14:56:51",
         "7. Time Zone": "UTC",
         "8. Bid Price": "0.82290000",
         "9. Ask Price": "0.82300000"
     }
}

===============================
Failure Example 3 for another currency other than USD

Request:
https://www.alphavantage.co/query?function=CURRENCY_EXCHANGE_RATE&from_currency=XAU&to_currency=AUD&apikey=MK...>8

Reply:
{
     "Error Message": "Invalid API call. Please retry or visit the 
documentation (https://www.alphavantage.co/documentation/) for 
CURRENCY_EXCHANGE_RATE."
}



Thanks