IFE....another computer driven system that sometimes causes more trouble than it's worth.
It's common for a % of seats to just drop out/play up, etc. Sometimes this can be fixed by a reset of the individual seat. If that doesn't work, then resetting the entire pax system is necessary, and it can take a long time. 20-40 minutes rings a bell. And whilst it might fix the offending seat, it's just as likely drop some others out. There is a further level of reset available on the ground, but that pretty well involves shutting down the entire aircraft, and not only will it take quite some time to come back to life, but it has a nasty habit of causing things (unrelated to IFE) that were previously working nicely to then play up.
Sometimes I dream of analogue.....