YEESSS ! I have found !
//ai_main.c
int BotAI(int client, float thinktime) {
char buf[1024];
[...]
//retrieve any waiting console messages
// Gordon: you MUST do this to acknowledge any commands sent
while( trap_BotGetServerCommand(client, buf, sizeof(buf)) );
[...]
Thanks to gordon’s comment 
Now that works well 

