bpy.ops.wm.open_mainfile jam the socket ?

[ZORN8496]

im using blender at window platform, and using pycharm to send command.
normally works fine.

but when i pass open_mainfile cmd:
send_command("bpy.ops.wm.open_mainfile(filepath='E:/AssetLibrary/Character/bl_rigs/ball.blend')")

it work only one time , blender well open file, and it seems the socket is block and jam, i can't either pass another new cmd or close port , even i reopen blender still not working ,

unless i restart my computer, and i repeat what i did, it will appear the same issues