If you catch the fish, and can massage the upper jaw back into place, and it moves with pressure, it could be simply dislocated.
If it seems frozen, impossible to move, this may indicate the atrophy of duck lips (columnaris).
What is the temp of the water in the tank?
82'F and above are prime duck lips temps.
Does the bass just kind of hover in one spot?
Has it eaten or not in those 2 days?
Both signs of columnaris.