The only time I have every experienced the "camera failed" error message was when I replaced a US model camera with an International model camera. The US and International versions of the phones have different cameras and they are not compatible with each other. It appears that iFixit only sells the US Model camera. This is notated on the back of the camera flex cable where it has the model SM-G973U, whereas the International camera should have the model number SM-G973F. Therefore I believe that the issue is most likely that the camera iFixit sells is not compatible with the International model of the Galaxy S10.