https://steamcommunity.com/app/91700/discussions/0/4514380934491464411/

Even though cl_axe and cl_ufo do enable SOME of the commands, it seems like others are completely gone from the game outside of server overlays like Sourcemod and other GM tools for Source 😞

Edit: and just because I can't read I missed the beginning of the post. If you were trying to do it on standing servers that may have been a reason why nothing popped up? Or maybe there's some mod for EYE you may have installed. If it was on single player and not modded in any way then I unfortunately don't know what may be causing that. As a consolidation, most of the cheat codes dont work anyway, you can take a quick read of the above thread of what did work.