Rivian Body Bolts for R1T and R1S feature a specialty head and require a specialty TP55 bit for bolt removal and installation.  This is an 'impact rated' heavy duty bit, suitable for use in a socket or with an impact wrench / gun.   

Note - Rivian has also used a T55 bolt in their service channels.  Chance are your Rivian came with TP55 bolts.  The T55 bit is slightly different than TP55, but the bolts are interchangeable (note - different socket driver is used for TP55 and T55)