See if you can recreate the problem, and collect your debug logs (not verbose)
There was (or is) some problems with hardware transcoding on some of the J-series Celeron CPU’s.
My J4105 is currently working so I haven’t been keeping a close eye on the status. This is a related thread if you want to take a look.
My guess is that you’re possibly needing to transcode something and it’s using software instead of hardware and the chip is just not powerful enough
ChuckPa is the Synology person here but the first thing he’s going to do is ask you for logs
If my hunch is wrong, that will give him the info he needs to help
