How to reproduce:
1. Open user attached 'Svg UI Repro.zip' project
2. Open 'SampleScene' Scene
3. Select 'Mask' child of 'Canvas - Screen Space Camera + RT' GameObject in the Hierarchy
4. Move Fill Amount Slider in the Inspector
5. Observe the Game View

Expected result: Mask is not being rendered into RenderTexture in Game View when Render Mode is set to Screen Space - Camera or World Space
Actual result: Mask is rendered into RenderTexture in Game View when Render Mode is set to Screen Space - Camera or World Space

Reproducible with: 2019.2.b10, 2019.2.12f1, 2019.3.0b10, 2020.1.0a12
Not reproducible with: 2017.4.34f1, 2018.4.12f1, 2019.2.0b9

Note: not reproducible with Screen Space - Overlay Render Mode