but they're there, i can see them with jade mod

CodeChicken Lib 1.18.2-4.1.0.460-universal
Ender Storage 1.18.2-2.9.0.177-universal

I have the same issue

Items that were put into an ender chest or ender pouch are not rendered again after closing the inventory screen. Causes unexpected item behaviour. Items are visible by Jade and can be pulled by a hopper.

Yes, i also can import the items to refined storage system without problems, apparently it's just the render when opening the chest that is bugged

You can place the ender bag into itself as well. Shift-clicking items into the pouch also causes inventory issues if there are invisible items.

i am having a similar problem where it appears the ender chest is voiding items
but when i attach a hopper to another ender chest they appear there but not in the chest it's self

This should be resolved by updating to CodeChickenLib 4.1.0.461 (pending approval on CurseForge)