Trouble finding information on my grandfather.

So I am looking for information on my grandfathers family. I have taken the ancestry DNA test, I found loads of information on my fathers mother and father dating back to the 1700s my mothers moms family has a lot of information going back around 3 generations but my mothers father has no info as if he doesn’t even exist! I had my mom do a DNA test and same results zero info on her father, the only pieces of information found is his voters info connected to 3 of his addresses in Ontario in the 60s and 70s after that nothing. Any advice?