Statistically significant bad results?

I have about 16.5k bets. Previous months, good and great results… but…
Around the 3rd week of october there was a problem with the software.
I did not point it here because it only last a couple of days.
The problem was: in the main window, the VALUE COLUMS showed NEGATIVE numbers, but when I opened the bet, it showed positive results. I thought 1 of the 2 numbers were wrong, so I betted anyway.
BUT, since that problem, my graphic curve is only descendind. I am not talking about ups and downs, I am talking about just downs. More than 1 month now, I am seeing a drop of 15% in my profit.
Maybe it is a bad streak, maybe the bookies I used this past month were horrible: sportingbet, 365, bethart, bettson, bethard, leo vegas…
I don´t know, but 15% in one month is kinda weird.