Light/Dim light settings under Advanced no longer working correctly

Setting up a dungeon and light sources for the players.  At first, I was able to correctly set up light sources, including light/dim light settings.  Suddenly, without warning, the advanced light settings no longer worked.  When I try to add a dim light component to a light source, it CONTRACTS the light source instead of expanding it.  If I have my light set to 30', I get 25' of light, and 5' of dim.  If I try to add a 10' dim light component to the light source, the full light component reduces by the amount of dim light I input.  I am playing with dynamic lighting, no fog of war.  I must have changed some settings somehow, but I cannot figure out what I did.  Any help would be appreciated.

The way I always understood how the lighting worked is the first number is the distance of the actual light and the second number is where it starts to dim from the edge of the light . By default the dimness starts on the last 5 ft of the light so you would get 25 ft light + 5 ft of dimness = 30ft of light. Now you are adding 10 ft to dimness but not increasing you light size. This means you are now seeing 15 ft light + 15 ft dimness = 30 ft of light If you want to keep the same amount of bright light while increasing the dimness, you might have to expand your light radius. 25 ft light + 15 ft dimness = 40 ft radius of light. This should make the first number be 40 then the second one would be 15. This is how I understand how it works.