Please, look at this GIF:

The label on the animation says "Move button is pressed, then released". And you can see when it's pressed (and player's getCenterY() is above wall getCenterY()), gravity doesn't work. I'm trying to fix it since yesterday, but I can't. All methods are called from game loop.

public void move() {
    if (left) {
            switch (game.currentLevel()) {
            case 1:
                for (int i = 0; i < game.lvl1.getX().length; i++)
                    game.lvl1.getX()[i] += game.physic.xVel;
                break;

            }
        } else if (right) {
            switch (game.currentLevel()) {
            case 1:
                for (int i = 0; i < game.lvl1.getX().length; i++)
                    game.lvl1.getX()[i] -= game.physic.xVel;
                break;
            }
        }
    }

    int manCenterX, manCenterY, boxCenterX, boxCenterY;
//gravity stop
    public void checkCollision() {
        for (int i = 0; i < game.lvl1.getX().length; i++) {
            manCenterX = (int) game.man.getBounds().getCenterX();
            manCenterY = (int) game.man.getBounds().getCenterY();
            if (game.man.getBounds().intersects(game.lvl1.getBounds(i))) {
                boxCenterX = (int) game.lvl1.getBounds(i).getCenterX();
                boxCenterY = (int) game.lvl1.getBounds(i).getCenterY();
                if (manCenterY - boxCenterY > 0 || manCenterY - boxCenterY < 0) {
                    game.man.setyPos(-2f);
                    game.man.isFalling = false;
                }
            }
        }
    }
//left side of walls
    public void colliLeft() {
        for (int i = 0; i < game.lvl1.getX().length; i++) {
            if (game.man.getBounds().intersects(game.lvl1.getBounds(i))) {
                if (manCenterX - boxCenterX < 0) {
                    for (int i1 = 0; i1 < game.lvl1.getX().length; i1++) {


                        game.lvl1.getX()[i1] += game.physic.xVel;
                        game.man.isFalling = true;

                    }
                }
            }
        }
    }
    //right side of walls
    public void colliRight() {
        for (int i = 0; i < game.lvl1.getX().length; i++) {
            if (game.man.getBounds().intersects(game.lvl1.getBounds(i))) {
                if (manCenterX - boxCenterX > 0) {
                    for (int i1 = 0; i1 < game.lvl1.getX().length; i1++) {

                        game.lvl1.getX()[i1] += -game.physic.xVel;
                        game.man.isFalling = true;
                    }
                }
            }
        }
    }
public void gravity() {
    game.man.setyPos(yVel);
}

 //not called from gameloop:    public void setyPos(float yPos) {
        this.yPos += yPos;

}