THIS IS NOT THE FINAL SOLUTION JUST A FIX I FOUND:

For whatever reason, my blind guessing fixed the problem:

If you change the edge_index in

bpy.ops.mesh.loopcut_slide(get_override(),MESH_OT_loopcut={"number_cuts":1, "smoothness":0, "falloff":'INVERSE_SQUARE', "object_index":0, "edge_index":131, "mesh_select_mode_init":(True, False, False)}, TRANSFORM_OT_edge_slide={"value":0.756757, "single_side":False, "use_even":False, "flipped":False, "use_clamp":True, "mirror":True, "snap":False, "snap_target":'CLOSEST', "snap_point":(0, 0, 0), "snap_align":False, "snap_normal":(0, 0, 0), "correct_uv":True, "release_confirm":False, "use_accurate":False})

from 131 to 130, suddenly everything works.

This is not the final solution just a fix I found:

For whatever reason, my blind guessing fixed the problem:

If you change the edge_index in

bpy.ops.mesh.loopcut_slide(get_override(),MESH_OT_loopcut={"number_cuts":1, "smoothness":0, "falloff":'INVERSE_SQUARE', "object_index":0, "edge_index":131, "mesh_select_mode_init":(True, False, False)}, TRANSFORM_OT_edge_slide={"value":0.756757, "single_side":False, "use_even":False, "flipped":False, "use_clamp":True, "mirror":True, "snap":False, "snap_target":'CLOSEST', "snap_point":(0, 0, 0), "snap_align":False, "snap_normal":(0, 0, 0), "correct_uv":True, "release_confirm":False, "use_accurate":False}) 

from 131 to 130, suddenly everything works.