I don't think you have a power problem. There are two main supply circuits. One is fuse 21, a 10A in the inside fusebox which you checked, the other is fusible link F, a 50A in the fuse and relay box. However, the fact that the lumbar switch still works means link F is good. Lumbar shares power with the other functions but is direct-drive from the switch, it doesn't go through the controller under the driver seat like all the other seat motions. The fact that the lumbar still works also means the driver seat ground is good. That means the most likely culprits are a bad driver seat controller or bad Auto Drive Positioner module (in the left lower dash near the steering column). Get a CAN scan from a Nissan Consult3+ or another high-end scanner that can see non-OBD systems. The ADP isn't connected to CAN but the driver seat control module is, and the seat then connects to the ADP on a pair of bit-bang LAN lines. So there will be codes in the driver seat controller if the ADP is incommunicado, which will mean the ADP is most likely at fault. On the other hand, if the driver seat controller doesn't show up on CAN, then it's the most likely culprit.