@hosseninimr93 I totally agree with you, because personally I have seen lower odds then what was shown when I wagered even at 99.99% weight multiplier.
Of course, the change in the odds isn't only due to that and it's possible that the final odds are even higher than the odds you see when placing your bet.
Freebitco uses parimutuel betting system and it's normal that the odds are not fixed. The odds depend on which outcome other users will bet on.