juniorIf listenserver.cfg is being executed on launch, it's probably because you're preloading mods. It shouldn't cause any problems.
If it doesn't work because cheats and/or wait are disabled (as they usually are after connecting to a real server), just enable them.
// listenserver.cfg sv_cheats 1 sv_allow_wait_command 1 net_fakelag 100; wait 150; net_fakelag 0
If it doesn't work because you need to select a class and spawn before cycling fakelag, you can fix it like so:
// autoexec.cfg alias cycle_fakelag_if_listenserver
// listenserver.cfg sv_cheats 1 sv_allow_wait_command 1 alias cycle_fakelag_if_listenserver "net_fakelag 100; wait 150; net_fakelag 0"
// scout.cfg soldier.cfg ... spy.cfg cycle_fakelag_if_listenserver alias cycle_fakelag_if_listenserver
god bless you bro, i used second way