I have created a simple scene in reality composer (composer not composer pro). It contains just a cube and text item.
I convert this to usdz file and load it into a Arkit swift app.
Since ios 18/xcode 16 - the "text" element is not displayed at all.
The cube is displayed, anchors correctly and can be moved etc.... The output from usdchecker
➜ Desktop usdchecker GKTUHR1.6.3.usdz -v --arkit
Opening GKTUHR1.6.3.usdz
Checking layer <GKTUHR1.6.3.usdz>.
Checking package <GKTUHR1.6.3.usdz>
Checking prim </Root>.
Checking prim </Root/Scenes>.
Checking prim </Root/Scenes/Scene>.
Checking prim </Root/Scenes/Scene/Gravity>.
Checking prim </Root/Scenes/Scene/sceneGroundPlane>.
Checking prim </Root/Scenes/Scene/sceneGroundPlane/physicsMaterial>.
Checking prim </Root/Scenes/Scene/Children>.
Checking prim </Root/Scenes/Scene/Children/hello>.
Checking prim </Root/Scenes/Scene/Children/hello/Generated>.
Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text>.
Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text/Material>.
Checking prim </Root/Scenes/Scene/Children/hello/Generated/Text/Material/PBRShader>.
Checking shader </Root/Scenes/Scene/Children/hello/Generated/Text/Material/PBRShader>.
Checking prim </Root/Scenes/Scene/Children/hello/Children>.
Checking prim </Root/Scenes/Scene/Children/Box>.
Checking prim </Root/Scenes/Scene/Children/Box/Generated>.
Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0>.
Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Mesh0>.
Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material>.
Checking prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material/PBRShader>.
Checking shader </Root/Scenes/Scene/Children/Box/Generated/Mesh0/Material/PBRShader>.
Checking prim </Root/Scenes/Scene/Children/Box/Children>.
Checking prim </Root/Scenes/Scene/Children/Box/PhysicsMaterial_Box>.
Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/sceneGroundPlane>. (fails 'MaterialBindingAPIAppliedChecker')
Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/hello/Generated/Text>. (fails 'MaterialBindingAPIAppliedChecker')
Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/Box>. (fails 'MaterialBindingAPIAppliedChecker')
Found material bindings but no MaterialBindingAPI applied on the prim </Root/Scenes/Scene/Children/Box/Generated/Mesh0>. (fails 'MaterialBindingAPIAppliedChecker')
Failed!