If you can post some examples of your securities and there ticker symbols I will test to ensure they are supported.
There are two methods within Moneydance for obtaining security prices automatically.
The extension “Quote and Exchange Rate Updater found under EXTENSIONS – MANAGE EXTENSIONS. Check you are running the latest build v1024. There is a bug in this extension in that as quotes are returned the values appear to be zero, although if the security is supported the security price history will update. For exchange rates use the source European Central Bank. Alpha Vantage covers the US as well as some securities outside the US, but is very, very slow. It’s my understanding that the source IEX Trading no longer works.
If the Quote and exchange rate updater does not work well for you try the free third-party Quote Loader. Both of the sources in the Quote Loader have good coverage of worldwide securities.