I wish this could be workaround, but materials still breaks, even if I upload all the different materials as different files. Every cube that is visible at same time should have different material and is from different fbx file
sketchfab.timeframe
0.25 1.fbx+21.fbx+31.fbx
0.25 12.fbx+22.fbx+32.fbx
0.25 13.fbx+23.fbx+33.fbx