[Pierre-Marie Baty]

this is normal because you must consider that client commands are sent individually.
If a real client can send client commands in a burst separated by semicolons (e.g, "buy;menuselect A;menuselect B"), it's because his client DLL separates each command and calls the client command function THREE TIMES. Once for "buy", another time for "menuselect A", another time for "menuselect B".
The FakeClientCommand() function you are using does not permit to do that. One or two years ago I wrote a different version of FakeClientCommand() coupled with pfnCmd_Argc, Argv and Args, that implements this behaviour and enables bots to send client commands in the same way humans do (i.e, with semicolons to separate each). It is implemented in POD-bot 2.6mm, if you want to give it a look.