Spigot 1.12.1 latest
MH 5.0.8

Occasionally, if I kill (at long range) two mobs, there is only one bag of gold when I arrive to collect. The bag of gold is the value of only one kill (ie., not a doubled amount). There are two experience orbs, and I saw the mobs die, so I am certain that two kills occurred.

I tried to reproduce. Since I was hunting with arrows (long distance), it is quite possible that the bags were destroyed by arrows. Enough...

Please enable /mh debug and check the console log when this happens. You can destroy the bag of gold by hitting it with an arrow or a fireball or something.

I will try to reproduce it, but I did mention occasionally . :)

I think I have found a temporary workaround. The hidden information was changed when the player opened the Inventory in Creative Mode and all items was updated by Minecraft. I my case line 1 changed to "Decoration Blocks" so what I have done is to cancel the event when the BagOfGold is (re)placed in the inventory. This works and the Item seems to keep its value now, buy the downside is that the item cant be moved anymore while the player is in Creative mode. It can be dropped and picked up, but mot dropped, halfed and so on.

Please help me with the testing, try build 476 or newer:
https://fractal.lindegaard.one:8181/job/MobHunting/

UPDATE:

Dont mind that the status is red, this is only because the build could not be uploaded to my Artifactory Server.

The jar is fine. http://jenkins.lindegaard.one:8180/job/MobHunting/476/artifact/target/MobHunting-5.1.2-SNAPSHOT-B476.jar

Spigot 1.12.2 latest
MH 5.1.2
Configured for dropped bags of gold, which must be picked up to gain awards.

Reproducible scenario:

Creative mode: Dig a 2x1 block hole, two blocks deep (so the zombies cannot escape). Place two zombies in it. Clear the area of other monsters (so you don't have to fight them during the test); fence the area if necessary to keep it clear. Move ten meters away.

Survival mode: Kill one zombie with arrows aimed at its head (you're ten meters away). The particles "pop" and the bag of gold drops (you can see the lore). Kill the other zombie with arrows aimed at its head (this should not impact the bag of gold, and does not appear to do, since you can still see the lore). The particles "pop" again. But, there is only one bag of gold, valued as for one zombie. Go into the hole to collect. Only one award is collected. That is, the economy balance increases only one zombie worth. The other bag seems to be MIA.

I have not been able to reproduce the MIA bag of gold. After disabling grinder detection, I was able to test repeatedly. I tried skeletons and zombies. No joy. :(

Here is an example:

[16:06:47 INFO]: [MobHunting][Debug] ======================== New kill ==========================
[16:06:47 INFO]: [MobHunting][Debug] rambeau killed a Skeleton (Minecraft)@(world_blackdog:38,71,11)
[16:06:47 INFO]: [MobHunting][Debug] Basic Prize= 50 for killing a Skeleton
[16:06:47 INFO]: [MobHunting][Debug] Multiplier: Sniper = 1.5
[16:06:47 INFO]: [MobHunting][Debug] rambeau has no Rank Multiplier
[16:06:47 INFO]: [MobHunting][Debug] Killstreak=3, level=0, multiplier=1.0 
[16:06:47 INFO]: [MobHunting][Debug] [AchievementBlocked] Achievements is disabled in world:world_blackdog
[16:06:47 INFO]: [MobHunting][Debug] RecordKill: rambeau killed a Skeleton (Minecraft) Cash= 75
[16:06:47 INFO]: [MobHunting][Debug]  75 was dropped on the ground as item SKULL (# of rewards=1)
[16:06:47 INFO]: [MobHunting][Debug] Command will be run if chance: 0.0 > 0.21088521740699617 (random number)
[16:06:47 INFO]: [MobHunting][Debug] ======================= kill ended (37)=====================
[16:06:49 INFO]: [MobHunting][Debug] ======================== New kill ==========================
[16:06:49 INFO]: [MobHunting][Debug] rambeau killed a Skeleton (Minecraft)@(world_blackdog:38,71,11)
[16:06:49 INFO]: [MobHunting][Debug] Basic Prize= 50 for killing a Skeleton
[16:06:49 INFO]: [MobHunting][Debug] Multiplier: Sniper = 1.5
[16:06:49 INFO]: [MobHunting][Debug] rambeau has no Rank Multiplier
[16:06:49 INFO]: [MobHunting][Debug] Killstreak=4, level=0, multiplier=1.0 
[16:06:49 INFO]: [MobHunting][Debug] [AchievementBlocked] Achievements is disabled in world:world_blackdog
[16:06:49 INFO]: [MobHunting][Debug] RecordKill: rambeau killed a Skeleton (Minecraft) Cash= 75
[16:06:49 INFO]: [MobHunting][Debug]  75 was dropped on the ground as item SKULL (# of rewards=2)
[16:06:49 INFO]: [MobHunting][Debug] Command will be run if chance: 0.0 > 0.9186707090853843 (random number)
[16:06:49 INFO]: [MobHunting][Debug] ======================= kill ended (37)=====================

Any suggestions as to what else I might try?

What does The server log show, With debug enabled (/mh debug)

Tried several times, but could not replicate in debug mode. AFK for a while. I will try again (late) tomorrow.

One thing I noticed:

[00:10:56 INFO]: [MobHunting][Debug] A reward was picked up by a ZOMBIE
[00:10:56 INFO]: [MobHunting][Debug] The pickup event was cancelled

every tick after I killed the first one. I guess there is no way to set the zombie to not pick up the bag.

There is no setting where you can deny Zombies to pickup items (and the rewards I have made) This is a Minecraft thing. But I can cancel the event, when a Zombie picks up a reward. And this is what you see here:

[00:10:56 INFO]: [MobHunting][Debug] A reward was picked up by a ZOMBIE
[00:10:56 INFO]: [MobHunting][Debug] The pickup event was cancelled

And I can only fix bugs which are reproducible :-) I can find a solution to a problem which I can not test....

I understand completely. I am trying to construct a reproducible scenario. So far, no joy.

After over 100 trials, I am unable to reproduce this issue. I give up. If I stumble across the secret sauce, I will reopen the issue (or open a new issue). Thanks for your patience.