Lighting won't work unless present on first compile

I’m having a strange problem with lighting. If I don’t have any lights, it appears fullbright, just as it should. However, if I later add lights after I had already compiled, it’s still fullbright. On the other hand, if I don’t compile it until I already have lights, the lighting appears as it should. (light_environment is kind of dark, but that’s another story.) If I then remove the lighting and compile, it’s fullbright. If I add lighting and compile yet again, you guessed it: fullbright. Can somebody please help me? Thanks!

mat_fullbright 0?

Do said lights have a brightness?

Just making sure, have you recompiled?

leak?

Yes (I mentioned that already), but I haven’t quit the game and relaunched it. Somebody mentioned mat_fullbright 0; I’ll try that tomorrow.