[Pierre-Marie Baty]

If you want your bots to wait 60 seconds before joining each time a new map start, then this
bot_check_time = gpGlobals->time + 60.0
should rather be put in ServerActivate(), because ServerActivate() is the first function called when a new map is about to start.

There are several ways in the code that lead to a bot being added. Do a search for each BotCreate() call, and check which one is called on the first map and which ones are called for the following ones. The difference among the checks that lead to BotCreate() will tell you all that you want to know.