I feel like this is the same issue I dealt with some time ago. Look into this thread, and maybe it helps you figure out what’s going on.
So basically as I understand it’s due to OpenGL vs DirectX conventions I guess (so (0,0) coordinates being left top vs left bottom). So basically, if you are loading texture manually in the code, the solution to above thread should work for you as well (last parameter “false” indicates that you want to flip the texture vertically aka invertY). Now, I am not exactly sure what to do when you export the GLB file with embedded texture. Is there a property like myTexture.invertY = true??. I did a really little bit of research and couldn’t find it. So you can look into that. Alternatively, scaling the texture with negative value could be workaround. So something like