THeir is an issue with 3.8 with the lang file and the code. It is fixed in 4.0 which you can try here if you like. I would like to get the input

(and the txt file)
Their are also new cvars.
Code:
//AFK Manager
--
amx_ammune_access a // Acces flag for immunity / Will not kick any admin with this flag
amx_immune_time 5 // Connected user's unassigned kick immunity time (How much time they have before their checked to get kicked)
amx_max_afktime 45 // Max. allowed AFK time (seconds)
amx_afkcheck_allow 1 // Enable / Disable this option in the AMX Super