Recently I found this bug where the playback goes more “slower” for large sequences when the speed is set faster. For smaller sequences, in the playback it switches to the next images quickly within less than a second. But for large sequences (around >150 images) it takes 2-3 seconds to switch to the next image when the speed is set faster. On the other hand when the speed is set slower, it switches to the next image faster, although the image transition effect is slow.