Does it need or require or function better grounded; if so where is best location to attach?

Additionally, I really like the information the display reveals. My application is utilizing a safety gap or spark gap which really seems to mess with the ‘constant voltage’ monitoring aspect of this device, causing the display to shut down or give a white screen. Still works at last preset but to adjust; an ‘off then back on reset’ is required. Think I am asking too much of this cool device…..True/False

thanks Scott