How to reproduce:
1. Open attached project
2. In Hierarchy select Trail and in Trail Renderer component make sure Mask Interaction is set to Visible Inside Mask
3. Move Trail around Scene
4. Notice that no other trails are rendered outside of the Mask
4. In Trail Renderer component set Mask Interaction to Visible Outside Mask
5. Move Trail around Scene

Expected result: No trail is rendered inside Mask
Actual result: Trails are rendered Inside the Mask

Reproduced with: 2022.1.0a13
Mask Interaction was introduced in 2022.1.0a7

Notes: Also reproduces with Line Renderer, but then several materials start z-fighting