Object disappearing due to high aspect ratio

Hello everybody, I have been using joule heat module to simulate the quench propagation in 60 cm long superconducting thin film. The thin film with the structure of Au/YBCO/sapphire is made of a 100 nm thick gold layer, a 300 nm thick superconducting layer and 0.5 cm thick substrate. But the problem is that the gold layer object automatically disappear in materials interface and joule heat module interface if I define length of thin film beyond 40 cm long.

Any solution is appreciated. Thank you.