Unsupported element type

### Describe the error

The arrows can't be displayed correctly. There is only a tip on top.
### Code and Error
**Code**:

manimgl vex.py

**Error**:

WARNING You may be using Windows platform and have not specified the path of `temporary_storage`, which may cause OSError. So it is recommended to specify the config.py:232
`temporary_storage` in the config file (.yml)
WARNING Unsupported element type: svg_mobject.py:174
WARNING Unsupported element type: svg_mobject.py:174
WARNING Unsupported element type: svg_mobject.py:174
WARNING Unsupported element type: svg_mobject.py:174
WARNING Unsupported element type: svg_mobject.py:174
WARNING Unsupported element type: svg_mobject.py:174
WARNING Unsupported element type: svg_mobject.py:174
WARNING Unsupported element type: svg_mobject.py:174
0 WriteText: 40%|#####################################################6 | 12/30 [00:00<00:00, 28.87it/s]
(process:19896): GLib-GIO-WARNING **: 20:46:50.113: Unexpectedly, UWP app `Clipchamp.Clipchamp_2.5.5.0_neutral__yxz26nhyzhsrt' (AUMId `Clipchamp.Clipchamp_yxz26nhyzhsrt!App') supports 41 extensions but has no verbs
[20:47:00] INFO Tips: Now the embed iPython terminal is open. But you can't interact with the window directly. To do so, you need to type `touch()` or `self.interact()` scene.py:152
Python 3.8.0 (tags/v3.8.0:fa919fd, Oct 14 2019, 19:37:50) [MSC v.1916 64 bit (AMD64)]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.6.0 -- An enhanced Interactive Python. Type '?' for help.

### Environment
**OS System**: Windows 11
**manim version**: master 1.6.1
**python version**: 3.8