StringBuilder marshalling causes runtime “free(): Invalid Pointer” abort signal crash on IL2CPP build

How to reproduce:
1. Open the user-attached project (MirageGoesBoom.zip)
2. Build the Linux standalone player with IL2CPP and .Net Standard 2.1 Runtime enabled on Windows
3. Run two instances of the build
4. On the first instance press the "Start Host" button
5. On the second instance press the "Only Start Client" button
6. Observe the first instance crashing

Reproducible with: 2021.3.16f1, 2022.2.2f1
Not reproducible on: 2020.3.43f1, 2023.1.0a22 (built on Linux since Windows doesn't support Linux IL2CPP builds on this version)

Reproducible on: Linux Build
Not reproducible on: Windows Build

Notes:
1. The builds fail when building on Linux except on 2023.1.0a22
2. Couldn't test to find the regressed version of the issue due to the long testing time and builds failing on Linux 2020.3, 2021.3, 2022.2 streams on Linux