automate bypass all

hi,i want to automate the bypass all inserts button at bar 16,then bak on at bar can i do this that i play from bar 15,hit bypass at 16 then turn bak on for bar 17.
i have tried all settings of automation,but dosent recoed the automation how i want.
when i press play at 15 the bypass is lit and dosent turn off till bar 17.