Incorrect calculation of the position at the transition in CUT mode [GPU Effect ON]

Linux Mint 21.2 Cinnamon

I’m creating a 30 frame transition. I set the mode to “cut” and the position to 50%. Logically, 50% of 30 is 15, and in the mode with graphic effects disabled, this is what happens, everything is fine. But for some reason, in the graphics effects acceleration mode, 50% of 30 frames is 8, and in order to achieve a cutout at the desired point, I need to set it to 70%. I think this is a bug.