It's probably because you don't have enough exercise intensity or the wrong method.
Strength exercisers mainly train at 90%- 100% of their own weight. Generally, each group can only do 1-6 times with all their strength, and they have to constantly hit their own limits. This method is very effective in increasing strength, but the muscle growth is very slow.
If you want to grow muscles, you need scientific exercise, not unplanned exercise. If you don't exercise for a long time, your muscles will shrink and lose their elasticity, so you need to exercise regularly. You can't dry the net for two or three days.
If you want to build beautiful muscles, you should exercise 2-3 times a week. After exercise, give your muscles enough rest time. Exercising a muscle every day can not increase the muscle well, but also make the muscle tired. Every exercise should have the best swelling and strength of this muscle, so that you can supplement protein and have a proper rest. If you are a beginner, you can see the effect after 2-3 months.