23M Astigmatism, New prescription blurrier in left eye compared to old prescription

My prescription went from -1x170 / -1x15 to -1.25x170 / -1x10. I put on my new glasses today, but for some reason my left eye is blurry (I have no problems with my right eye); this didn't happen with my old glasses. The people at the optician's told me I might need to adjust. Is this normal or a thing?