The animation doesn't show on item drop or pickup from the Trash Slot mod.
https://www.curseforge.com/minecraft/mc-mods/trashslot

Here's a video demo:

Strange. This mod should work with all slots unless the mod is doing something peculiar. I'll see if this is something I can fix on my end, but it might be something the authors of the trash slot mod should look into.

Seems like the Trash Slot is not a normal slot, according to the mod author, so TIA would need to add its own support for it:

TwelveIterationMods/TrashSlot#123 (comment)

Might look into this in the future then.

hope you can find a workaround for this issue.