It’s in-between eastern and semi-western,usually referred to as extreme eastern, with Federer being the most renown user thereof. You can perfectly drive the ball with this grip. First thing I would look at/for - extending past the ball as you hit, avoid trying to “snatch” the racquet anywhere - accross, over the shoulder, straight up - just let it go.
Next - check if you hit the ball very high, so swing from low below the ball. Shoulder level and higher is suboptimal. Let the ball drop more while preparing more level with the contact point.
If it’s the opposite, and you hit the ball pretty low, yet create a loopy weak shot, it’s likely you approach the ball improperly - give more sideways spacing, swing outward, hit forward and through rather than pump it from below with an open racquet face.
