Once I make a Solar Board and when I spark NSCN (Fix me if I wrong at the names) its transfer the spark to PSCN! There is no problems at the Solar Board. Just this bug.
If you mean solar panel by "solar board" then it's intentional.Thin layer of PSCN over NSCN comducts SPRK when photons touch this arrangement.
See this for more information https://powdertoy.co.uk/Wiki/W/Element:PSCN.html