I'm on a 1.21.5 Paper server

When void bundle or mob bag has item or mob in it, when used to pull them out, nothing comes out.
Seem to happen to all players in the server.

Datapack originally worked for a while until it stopped one day.
Although, I did mess with the server a lot(adding plugins and datapack).

Could you send me a list of your plugins and datapack? Also a list of your clientside mods (if any)

When you use the mob back or void bundle, does it make any noise or display any sort of particle effect?

I could list them, but I'm pretty sure it's no use. I use a lot of plugins and datapack(about 70 total). Because of it I was only wondering if you already knew cause of it.
If you still want list of them, tell me.

And yes, it does make particles and effect.

This is an issue that I've seen previously, and is normally caused by a conflict. The mob bag and void bundle work just fine on paper servers on 1.21.5 normally

A list of installed mods/plugins/datapacks would be useful, so I can check to see if the cause of this bug is the fault of something else you have installed

Not sure when exactly when this start to happen, but my guess is it happened with stellarity datapack?
I put image of my server. They should be in recent order.
If you can't find problem, no worries, I still enjoy you datapack. I don't have to use mob bag(void bundle still works just can't pull out item!)

Update

I found what it conflicts with.
Stellarity does have its own bug but is not the main cause of it. Also mob bag have a bug.

They are all tested on a brand new server(1.21.5 PaperMC) with only datapacks I mention on it.
Links are short clip of my testing.

First one is just have your datapack installed.
Haven't test all mobs, but so far, mob bag seems to not work with some water mobs.
They don't spawn on the ground or inside water.
https://drive.google.com/file/d/1bvvlAvGyat1VIGG1c9Ce5_ebk4IkQE3e/view?usp=drive_link

Second one is JakeTools and Stellarity.
With void bundle, when bag is held to delete items, it refreshes every time it picks up a item so bundle don't fill up.
With Stellarity also installed at the same time(did not matter the order they are installed, tested both order), bundle doesn't immediately refresh and continues to fill up until it is put down.
https://drive.google.com/file/d/1TxY-xYoQCEGDzb1E23bZAhHsY0O6Hsoo/view?usp=drive_link

Third one is two from above plus datapack called Ray's Pet Teleport Fix.
This one is the one that cause the problem.
When installed it, both void bundle and mob bag won't give out what is inside of them.
For mob bag, you can also see that when you check item after picking up mob, their name doesn't show up either.
https://drive.google.com/file/d/1A-l9TE7m90cJLxcJMDtkPRNUJiguWenC/view?usp=drive_link

Hopefully this helped you. Love your datapack btw.

The first issue seems to be a thing with despawning rules for certain mobs, I have a fix for that and it will be in the next update

The second issue, the "continues to fill up until it is put down" bit only happens in creative, this is just something that Minecraft does with the creative cursor slot. I'll need to do further testing with Stellarity

Ray's Pet Teleport Fix removes all loaded chunks on server/world start. This is not a brilliant practice as a lot of packs (like mine) use loaded chunks for core functionality. Please make the developer of that pack aware of the issue

Thanks for your response!

For the second one I guess I was dumb XD.
If that was just creative problem, I guess Stellarity is fine. I haven't seen any other bugs with it.

Ok upon further investigation, the first issue only occurs with squid, glow squid and bats. This seems to be a genuine minecraft bug which I have opened here: https://report.bugs.mojang.com/servicedesk/customer/portal/2/MC-299295

There's sadly no workaround right now, so you'll have to wait until the bug is fixed for the mob bag to work on those entities

I see. Although, as shown on the video, tropical fishes also have same issue. I don't know if there are more like this, but is that something you can fix or is it similar situation like squid as well?

Try using the most recent version, it might fix your issue. If not, then I suspect it's being caused by that bug

I'll try later.

Also I know this is not the place to ask, but I don't really know anyone to help me with and you seem to be really good with datapacks.
I understand if you ignore this comment.

I'm trying to make custom food with their own recipe.
I never learned how and today's my first day trying this out.
I have resourcepack working but datapack doesn't load any recipe.

Inside datapack, it has pack.mcmeta, data/nsnd/recipe/hamburger.json
json file is

{
"type": "minecraft:crafting_shaped",
"pattern": [
"B",
"S",
"B"
],
"key": {
"B": "minecraft:bread",
"S": "minecraft:cooked_beef"
},
"result": {
"id": "minecrat:bread",
"components": {
"minecraft:item_name": "hamburger",
"minecraft:item_model": "nsnd:hamburger",
"minecraft:food": {
"nutrition": 8,
"saturation": 9
}
},
"count": 1
}
}

The result id is misspelled, and the pattern needed spaces:

"pattern": [
    "B   ",
    "S   ",
    "B   "
]