Version Info

• Minecraft, 1.21.1
• Trash Cans, trashcans-1.0.18a-neoforge-mc1.21
• Core lib, supermartijn642corelib-1.1.17f-neoforge-mc1.21

Description of the Bug
None of the trashcans are showing up in jei. They show up in the creative menu and if you spawn one in and check recipes the recipe is there/show but searching for it in JEI doesnt show up

Just Enough Items is supposed to show all items which appear in creative tabs/search. What you describe seems like a bug with JEI.

this is happening with all of your mods specifically but most other mods like mekanism etc dont seem to be impacted. I can open an issue over there with Mezz as well if you suspect its on jei's side though np!

So far Entangled, item collectors and Trashcans dont show up in JEI but connected glass and simple magnets do

In 1.20.6, NeoForge added a creative tabs API which fires an event for each creative tab. The event then allows adding items to the respective creative tab.
There are two ways to add an item to the creative search tab through the NeoForge API:

• During the event for some creative tab, add the item to that tab with the PARENT_AND_SEARCH_TABS flag
• During the event for the search tab, add the item to the tab

It appears JEI ignores the latter and does not display any items added to the search tab during the search tab's event.

In 1.20.6, I simply added items to any creative tabs with the PARENT_AND_SEARCH_TABS flag including the search tab. This meant items did end up showing in JEI by being added to the search tab through the other creative tabs.
In 1.21.1, NeoForge changed it so their API throws an error when an item is added to the search tab and it is added to a creative tab with the PARENT_AND_SEARCH_TABS flag. As such, I add the items to any creative tabs with the PARENT_TAB_ONLY flag and also add them to the search tab.
As JEI ignores any items added to the search tab directly, the items from my mods do not show up in JEI.
I believe this is a bug with JEI. I am not sure if this behaviour from JEI is intentional, but it would seem somewhat odd to me.

ok i've opened an issue over on jei's tracker now for follow, thanks for looking into it!
mezz/JustEnoughItems#3723

Mezz said this was indeed a jei issue and fixed in the next update so you can close this whenever you like, ty for looking into it!

Thank you, glad to hear it's fixed