
I'm not using BA but looks to me like it's not a software related issue, just that their API is showing the amount incorrectly. Same thing happens whether I place bets with the software or via BF website.
However, it's not a fixed % from what I saw today. I placed an unmatched bet at 2.0 of €1000 and it showed €1010, but 10 mins later it showed €1005 instead. Same market and same price, so idk what's going on.