DIAGNOSIS: No, that's not normal runtime, even for Max mode. You should get around 8-12 minutes on Max. This points to either a severely aged battery, a battery that wasn't fully charged, or something causing the motor to overwork and drain power fast.
FIX: First, rule out a charging issue. Let the battery charge on the dock, plugged directly into the wall, for a full 4-6 hours. The light will go solid, but give it the extra time for a 'trickle charge' to top it off. Then, run a test on a bare hard floor with no attachments—just the handheld vacuum. If it still dies in 5 minutes, the battery is likely the culprit.
IF THAT DIDN'T WORK: If the battery performs fine in the handheld test but dies fast when the floor nozzle is attached, you have a different problem. A clog in the system or a brushroll bound with hair forces the motor to draw maximum power constantly, which will kill a charge in minutes. Do a full clog check and brushroll clean.
HEADS UP: Battery lifespan is measured in charge cycles. If you've been using and charging this vacuum daily for a couple of years, the battery simply wearing out is the most likely answer. They're consumable parts, like tires on a car.