Welcome to Allpar. There are no dedicated fuses for the taillamps. The left and right sides are controlled independently through the BCM.
If the BCM senses a problem in one side, it can shut off power to that side for protection, store a useful fault code and run tests. You may need a capable scan tool (i.e. - WiTech2 or equivalent) to properly diagnose this.
From the service manual:
"Conventional diagnostic methods will not prove conclusive in the diagnosis of the exterior lighting system or the electronic controls or communication between modules and other devices that provide some features of the exterior lighting system. The most reliable, efficient and accurate means to diagnose the exterior lighting system or the electronic controls and communication related to exterior lighting system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information".