[Bug]: The picture I drew is gone

[Nu1i]

Describe the bug

The picture I drew is gone.

To reproduce

1. Go to drawings
2. drawing on the blank area.
3. click math module.
4. click drawing module,the pic is gone. only blank.

App Version and Architecture

5.6.1

System info

System:
    OS: Windows 10 10.0.19045
    CPU: (8) x64 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
    Memory: 3.40 GB / 15.74 GB

Validations

• Follow our Code of Conduct
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.