I don't know if people will still look at this map anymore, but if there are still people that look at it and try to find a fix onto how to level their perks up, I have the exact fix for it, more or less. This is a quick thread for everyone that has issues with leveling up their perks.

When you enter the map, before doing that, go to Killing Floor gamemode (as you usually do), and before joining the map, make sure you have no mutators activated, if you do, you're screwed. So, just remove all mutators from the list that is on your right. Also, don't enable cheats cause we all know that some games on Steam deactivate the achievements and perks (in this game) if you activate cheats etc, so don't use them. You won't be able to level up your perk fast. As long as you don't have mutators activated and don't enable cheats, you should be good to go. When leaving the map, don't press "Forfeit", you will lose all of the XP you just earned. Neither press "Exit Game" cause then the save of the perks will not save in any way. If you have the console enabled (which you all should have enabled, or some of you) just type "disconnect", copy the word disconnect, and press enter, that way you will be redirected into the main menu then you should test out if your perks got saved on a simple solo game or just go into Multiplayer and test it on a server (some server that won't lag the crap out of you, my opinion).

A reminder before ending this, please check out one of the threads where it will help you use the map better. I'm not a professional in any kind when it comes to perk leveling issues, but this thread might be useful for some. Hope this helped you with your leveling issues, again, I'm not an expert when it comes to perks not being saved.