When I use custom profiles the bots occasionally go invisible but you can see where they are by the talking icon above their heads. When this happens they become unshootable except with explosives and often lack collision. When this occurs the following error is printed in the console:

[Lambda Players | The Zeta Player Sequel] NextBot [295][npc_lambdaplayer] lua/lambdaplayers/lambda/sh_util.lua:691: Tried to use a NULL entity!
1. func - lua/lambdaplayers/lambda/sh_util.lua:106
2. v - lua/lambdaplayers/lambda/sh_util.lua:79
3. unknown - lua/includes/modules/hook.lua:96