Minecraft 1.15.2
Forge 31.2.47
toms_storage-1.1.5.jar

MC with only forge and this mod installed, no config altered. Made a bunch of chests, loaded with stuff, attached a terminal, and it shows only contents of a chest directly behind it. Doesn't show the content of adjacent chests.

Basically, a serie of screenshots says it all: https://imgur.com/a/1A0KOtp

What's wrong?..

Hm. That's quite not obvious... why wouldn't you combine the functionality of Inventory Connector with Terminal?

You need an Inventory Connector behind the terminal. The terminal can only see the inventory it's placed on. The Inventory Connector combines the inventories into one.