The -fast compile parameter is the cause of that. If you read what fast actually does below, you'll kind of understand why it does that.
You can do what the wiki says above to compensate, but you can also do things like a key of _mingridlight in the worldspawn, with a light value for the value and it will bump up the light grids ambient value only rather than the entire map. However, I would just recommend removing the fast parameter from the compile and doing things the normal way.
I have personally found bounce 2 to not be worth the compile time. The detail is negligible in-game and most people wont notice unless you have a specific case that takes advantage of it. Which these maps definitely do not do. I usually do bounce 1 instead.
Using super is also part of your issue, again to quote the wiki:
This is the light parameters I use for a majority of levels:
-light -patchshadows -v -samples 4 -thresh 0.1 -bounce 1 -bouncegrid
Depending on the level, I'll add things like -filter, -samplesize, -bouncescale.