Idk if ypu ate using grease pencil for the outline but I thing the position of grease pencil has to do with what you see from camera view but I'm not sure
Maybe you can try adding an outline with texture

Congratulations on amazing improvement

I tried image reverse search and I found this, the art looks similar but I'm not 100% if the artists has other platform

Same here, I used 3ds max in first two years of uni but using blender I'm not sure if I'm good at 3d modeling or not. You motivated me to start improving my 3d modeling skills