Basically:

NRT-TPE: sat in 1K and didn't work and had to be reset multiple times, so I finally moved to 2K and it was OK, but the result being that I couldn't watch a full movie...very frustrating.

TPE-HKG: moved to 2K and it worked fine...watched CSI.

HKG-TPE: sat in 2K and it didn't work, moved to 3A and it worked OK.

TPE-NRT: sat in 3A where it had worked on the previous segment, but they fiddled with the system on the ground and so then it didn't work at all, nor did the other seats, despite numerous attempts to reset.

They gotta do something about this.