On more than one occasion I have landed at the bunkers to the Northeast of stadium and collected a red keycard at the beginning of a match. Immediately ran for the actual loot bunker and the card would not access those doors. Are the bunkers not accessible for a set amount of time at the beginning of the match? Are the keys bunker specific? Am I missing something? I have personally been the key holder and been on squads where my teammates have the key and those doors won't work. In those matches, it was always the beginning of the match and we never made it to another set of bunker doors to test the key on other doors.