1, bicycle transmission is not aligned. Just go to the bike shop and deal with this.
2. Your bicycle transmission system is a high-end model of Shimano. Multi-release is a patent of Shimano Company. Through multiple releases, you can switch two gears at a time (that is, click) to achieve the effect of switching to the best gear in the shortest time. This technology is equipped on XTR, SAN, DEO XT, Affin and R780 of Shimano.
If your bike is not equipped with these configurations, it is most likely the former possibility-the speed change needs to be adjusted.
Seek adoption.