I have a tvs50 integrated with DPITS to a td-816. I have programmed night/day mode times in the td-816, and set the switching mode to auto. When the 816 switches to night mode, the tvs50 does not. I can verify that the 816 is in night mode on the handsets, but the only way I can tell if the tvs50 is in night mode is whether or not it uses the custom service that I have selected. Any advice?