NavMesh not recognised in IL2CPP builds

We have recently run into some problems with navigation in a Quest 2/3 project. Navmesh agents which functioned perfectly in the editor were not working in our test builds for android. After some testing we've learned that when building for Windows or Android, if the Mono backend is available and used, everything behaves as expected, but switching to IL2CPP causes the below error messages, regardless of whether the navmesh agent is pre-existing or instantiated at runtime.

 

 

I have already tried many potential solutions including Warp() or setting position before enabling the agent, rebuilding NavMeshSurfaces at runtime before instantiating the agents, and have switched back to the legacy NavMesh system to rely on baked navmesh data, none of which have changed anything. We have tested with extremely basic Navmesh agent wander behaviour and it seems clear that the backend is somehow affecting the references to Navmesh or the mesh data itself.

 

Has anybody experienced this problem, or do you have any ideas for workarounds/solutions? I hope someone can help, thanks!