Potential bug with display of currencies?

I have a small problem with the display of currencies and wonder if this is a bug that has to be corrected:

I have set a few currencies, but let's see what happens with two of them.

Euro currency with Display Locale el-GR and Custom Formatting left blank: prices are displayed correctly, for example 1.234,59 € or 0,00 € as the locale dictates.

Dollar currency with Display Locale en-US and Custom Formatting left blank: prices are displayed correctly, for example $1,234.59 or $0.00 as the locale dictates.

(Note that the thousands separator is "." in the first case and "," in the second and the decimals separator is the other way around according to the locale set. Also note that the currency symbol is after the amount in the first case and before the amount in the second, again according to the locale).

Regardless of the locale, I wanted the amounts to show as €1,234.56 and $1,234.56 and tried to use the Custom Formatting field, something very common in Excel and self-explanatory. With this in mind, I set the custom formatting for € to €#,###.00 and to $#,###.00 for the $ currency.

Although the amounts show correctly as per the custom formatting, amounts less than 1 unit display as €.00 or $.00 with the integer part of the amount truncated if it is zero.

Trying to set the locale to en-US for euro makes things even worse: the price is displayed as $0.85 (EUR) if euro is the display currency and correctly as $1.05 (USD) if dollar is the display currency.

This doesn't seem correct. I had to clear the Custom Formatting field to temporarily overcome this issue but would like to be able to use it again if possible. Any suggestions or comments please?

I found a solution to this, although not 100% satisfactory. To correctly display values lower than 1 unit, the Custom Formatting should be €#,##0.00 or $#,##0.00 and that seems to work fine. However, the el-GR locale still overrides the Custom Formatting and displays "." instead of "," as the thousands separator. I hope to solve this too!