Im not sure if I can explain this right but I'll try.
It looks to me like you are hitting with your racket almost vertical rather than horizontal.
Another way to describe it is that you are drawing your racket across the ball from bottom to top of the racket face instead of from right to left side of the racket face. so your cross strings are now the ones imparting spin onto the ball rather than your mains.
Völkl PB10 Mid with some strings at some tension