I have been playing with some functions related to Wolfram Physics Project and most of the evaluated code, which should give some visual output (graphs etc.) ends up in producing mysterious gray rectangle. I have tested mostly codes from Technical Introduction and from Resources/Function repository, and some of them work, but mostly they don't. Also slight modifications of working line (such as changing number of iterations) usually gives such output. The problem appears to be not quite deterministic. I attach example of code taken from https://resources.wolframcloud.com/FunctionRepository/resources/MultiwaySystem?i=MultiwaySystem&searchapi=https%3A%2F%2Fresources.wolframcloud.com%2FFunctionRepository%2Fsearch
