I use clipping plane in rhino and surface broken

I use clipping plane in rhino and surface broken, but before this time everything is alright.
I just come to edit model and use clipping plane to convenience to make a model inside.

Help plz.

Before

After use clipping plane

Hello - Please run the SystemInfo command in Rhino and copy/paste the results here.

-Pascal

Rhino 6 SR1 2018-2-6 (Rhino 6, 6.1.18037.13441, Git hash:master @ 5a33e6871b94d32ba552468218cef0ad8d3d1263)

Windows 10.0 SR0.0 or greater (Physical RAM: 32Gb)

GeForce RTX 2060 SUPER/PCIe/SSE2 (OpenGL ver:4.6.0 NVIDIA 460.89)

OpenGL Settings
Safe mode: Off
Use accelerated hardware modes: On
Redraw scene when viewports are exposed: On

Anti-alias mode: 4x
Mip Map Filtering: Linear
Anisotropic Filtering Mode: Height

Vendor Name: NVIDIA Corporation
Render version: 4.6
Shading Language: 4.60 NVIDIA
Driver Date: 12-11-2020
Driver Version: 27.21.14.6089
Maximum Texture size: 32768 x 32768
Z-Buffer depth: 24 bits
Maximum Viewport size: 32768 x 32768
Total Video Memory: 8 GB

C:\Program Files\Rhino 6\Plug-ins\Commands.rhp “Commands”
C:\Program Files\Rhino 6\Plug-ins\rdk.rhp “Renderer Development Kit”
C:\Program Files\Rhino 6\Plug-ins\RPC.rhp “RPC”
C:\Program Files\Rhino 6\Plug-ins\RhinoRender.rhp “Rhino Render”
C:\Program Files\Rhino 6\Plug-ins\rdk_etoui.rhp “RDK_EtoUI”
C:\Program Files\Rhino 6\Plug-ins\rdk_ui.rhp “Renderer Development Kit UI”
C:\Program Files\Rhino 6\Plug-ins\NamedSnapshots.rhp “Snapshots”
C:\Program Files\Rhino 6\Plug-ins\RhinoCycles.rhp “RhinoCycles”
C:\Program Files\Rhino 6\Plug-ins\Toolbars\Toolbars.rhp “Toolbars”
C:\Program Files\Rhino 6\Plug-ins\3dxrhino.rhp “3Dconnexion 3D Mouse”
C:\Program Files\Rhino 6\Plug-ins\Displacement.rhp “Displacement”

Hello - You should update your Rhino, the current version is 6.34
https://www.rhino3d.com/download/archive/rhino-for-windows/6/latest

-Pascal

Just update ? okay, I will try
Thanks !