NavMesh Null error when Previewing world on browser/mobile

Hey! I'm seeing a weird issue where my NavMesh works perfect when previewing in the editor, but when testing as browser or mobile preview the NavMesh cannot be found. I'm seeing the exact same when testing out the NPC Examples tutorial as well as the Chop n Pop template world.

Anyone seen this before and have any pointers?

I see there is a 2 year old post with something that sounds similar but can't confirm if it's the exact same error. https://communityforums.atmeta.com/discussions/dev-unity/navmesh-not-recognised-in-il2cpp-builds/1199692