'Value of Deals Advanced' and 'Value of Deals Won' only track deals valued specified currency. So, for example, let's say you set a goal of advancing deals worth £100 a month, then advanced one deal worth £10 and one deal worth $1000.
The goal for that month would not be met as less than £100 of deals valued in £ were advanced from the specified stage. The deal of $1000 is not counted as it's in $ and not £, so only the deal of £10 is counted which is not enough to reach the £100 goal.
The way to solve this if you're working in multiple currencies is either to set up multiple goals, one for each currency (if you have currency-specific targets), or to convert the value of your deals into one currency before they're won or reach the specific marked stage.