Custom layers no longer visible in newly updated maps

[imvizar-chris]

Our Unity app (Unity 2021.3.11f1, Mapbox SDK v2.1.1) uses several mapbox map styles, each with a custom layer trail created from a .kml file. Last week we updated one of the map styles with a new .kml file, but found the trail layer no longer appeared in Unity, either in the editor or in builds. Existing maps are still working correctly, but updating a style or creating a new one results in the same issue. Changing the style to use .kml files which previously worked doesn't seem to make a difference.

Example of a style that does not work - mapbox://styles/imvizar/cltei5s0u00ns01qn3fuy0a7s
Example of a style that still works - mapbox://styles/imvizar/cl6z40z3z003b14o2vcut4fs6

Can you see any reason why this issue has started happening? As mentioned, there have been no changes on the Unity side, only updates to the style in mapbox studio, so the issue is unlikely to be at our end.