Just to update everyone:
Ordered another CAM1320 and NanoPi-NEO4 to troubleshoot. Second camera works perfect with both NEO4 boards. Second camera + FPC cable from the first camera works as well, so the issue is something hardware related on the first module.
Ordered another CAM1320 and NanoPi-NEO4 to troubleshoot. Second camera works perfect with both NEO4 boards. Second camera + FPC cable from the first camera works as well, so the issue is something hardware related on the first module.