devtrackers.gg
The restock timer added in latest update is buggy, it should restock every 30 minutes, but if you reroll and/or trade close to when it should restock, it messes up the timing (time shown is not the actual time at which it will restock).
The information I have available is that the system works as MadamCurie suggests.
If however you believe it is working incorrectly, a video would be much appreciated. We can review it and work on a fix if it is not working as intended
Thank you!