I believe the maximum digit length when placing a sports wager is 6 so if you try again using
0.00047393 it should work.
Yes, that was the reason for the problems and the "Invalid bet". To be honest, I'm surprised that the process of cutting the numbers when creating a bid is not automated.
Or at least, it would be great if something more specific was written in the message about Invalid Bet.
I turned the won free bet into $105 (in btc, of course) and successfully withdrew. Thanks for the contest.



By the way, am I somehow looking at the betting history incorrectly and is there a more convenient way?