Hello, 46.88 is the average price as per FIFO method which is used in some country such as Germany.
In France, we use the PRU, you can find in PP under the “moyenne glissante” name.
Your Broker calculates the average price as the average of ALL buys. PP calculates the average price ( by default) as the average of the open trades. If you sell stocks then the first buys together with the sell form the closed transaction ( FIFO principle).
In your case the first buy of 10 shares together with the sell forms the closed trade and only the second buy is left for the open trade.
But in PP you can also display the average price of ALL buys like your broker does.