Minecraft Version: 1.21.1
Fabric Loader Version: 0.16.5
Fabric API Version: 0.105.0
Tom's Simple Storage Version: 2.0.9

I have one instance of the Inventory Interface block actually working in my world and it is linked with an inventory cable to an attached Inventory Connector as described in the tooltip. It shows the attached inventory on the Jade on-screen tooltip when I mouse over. I can insert items into the interface and they go into the Storage system as expected.

Here is the working setup:

And below is a different Inventory Connector that is part of my main storage system and an Inventory Interface connected on the same inventory cable, but it doesn't work. Tried moving the Inventory Interface to different connection points, it only seems to work if it's directly touching the Inventory Connector block which kind of defeats the entire purpose of it. That does at least prove the interface works with that Connector, but it stops working if connected with via an Inventory cable.

I just noticed that v2.0.11 is out, so I upgraded to that but the issue is still present on the latest version.

It seems to get stuck on "Collecting Items..." shown in the Jade tooltip.