Version: 2.5.1
Expected behavior: relays retain information on where to send source to.
Actual behavior: one relay specifically keeps resetting on world reload.

Once I wand the relay and reprogram it, it starts to function normally.

I believe the issue might be that the relay in question does not have line of sight to its destination (another relay). All the others in the chain have a clear view of the destination, except for this one. Warp relays do not seem to have this problem.

Sorry for the vague bug report, I haven't had the time to properly test it (in part because the server takes forever to restart). As I gather more info on it, I'll keep this issue updated.

Edit: After a couple more days, it seems swapping it with a warping relay did fix it. However, we did notice that a splitter is also having an issue: it's always forgetting one specific target of theirs. The three targets (three warping relays) are in the same chunk, but not in the same chunk as the splitter. The target of the forgotten warper is closer than the other two's targets, and none of them are more than 5 chunks away.