Plateaus rarely have a single cause. Training volume, recovery, nutrition adherence and general life load all contribute.
Change one variable at a time and give it long enough to produce a signal — usually two to three weeks.
Your recorded history is what makes that possible. Without it, every adjustment is a guess.
This article provides general fitness and wellness information only. It is not medical, dietetic or personalised exercise advice. Speak with a qualified professional before making significant changes to your nutrition or training.