Due to this commit sponge will not tick computers outside of a set radius of a player. This leads to computers timing out and so shutting down when players re-enter the radius. There are a couple of possible solutions to this:
Suppress timing out for TileEntity computers (turtles and computers). This would mean computers continue to run, but do not update their environment (such as redstone or peripherals).
Detect timeout and set the start requested flag. The computer would shut down but would start when player's re-enter the tick radius.
Detect timeout and keep the computer on, just don't resume the computer thread. Computers would not shut down but would resume when they re-enter the tick radius. This may lead to issues with timings, I'd have to check. Some events may be discarded if there is a long network cable, resulting in other computers being ticked.
Due to this commit sponge will not tick computers outside of a set radius of a player. This leads to computers timing out and so shutting down when players re-enter the radius. There are a couple of possible solutions to this: