Uve plateud Because your body has probly been trained in the same intensity for a while now, training for str isnt the answer> you need to up the intensity of your workouts to make them more grueling to get that oxygen debt, str training will just make you go backwards for pysique gains. Also adding in functional exercises for added intensity will put a different stress on the the body that your muscles arent use to> Results= added growth.
You need to keep pushing urself hard, and that doesnt mean trying to lift more> it means adding more challenges to your muscles> to hammer the fuck out of your body so ur nervous system will be thinking holy fuck, what is happening, then you will start seeying improvements.