This was previously addressed in #69 but seems to have returned. Playing Life in the Village 3 pack with versions:
forge 43.3.2
toms_storage-1.19-1.5.9
StorageDrawers-1.19-11.1.2

If I have a bank of drawers and connect an Inventory Connector and Storage Terminal, the correct number of items is displayed.

If I connect a Drawer Controller to the bank of drawers, the terminal doubles the numbers. Note: the controller doesn't need to be touching the Inventory Connector, it gets found via the connected inventory.

I just found a workaround on my Prominence II RPG (Fabric) 2.7.0 server. I moved the Inventory Connector off of the chest and hung it off a cable away from the chests. All of my chests are now using Inventory Cable Connectors to connect chests to the inventory network. YMMV.

Same issue occurs with the Sophisticated Storage "Storage Controller" and that mod's barrels.

I'm having the same issue- I have a few iron chests from sophisticated storage and a storage controller connected and some of my items are doubled but not all of them. It's really annoying lol

I'm having the same issue- I have a few iron chests from sophisticated storage and a storage controller connected and some of my items are doubled but not all of them. It's really annoying lol

The trouble is that Tom's Storage is searching the chain of adjacent inventories. Each drawer/barrel/chest has its inventory, so Tom's finds each one in turn and adds it to the list, then it finds the controller. The controller's inventory is the sum of all that mod's inventories, so it adds it to the list, thus everything is doubled.

Tom's just needs to have some way to know what's a controller and if it's a controller, ignore all the other inventories that belong to that mod and just use the controller. Or at the very least, not search beyond the controller. That way you could carefully connect the controller but not the chests/drawers/barrels.

I swapped Tom's out for Simple Storage as that seems to work (at least for now!)

Same issue here

This is happening for me in 1.20.1 with Storage Drawers. If I put it directly on the strorage connector, I get a correct amount, but if I put it on an inventory connector next to the block, I get double. Very frustrating!

So I ran into this bug and it appears to only affect double-chests. This means that to keep chests next to each other, you'll need to shift + right click them on the ground; this will prevent them from trying to connect to nearby chests. My solution was to just use barrels, that way I didn't have to worry about accidently connecting the chests.

I'm using v2.0.9 for Neoforge on MC 1.21.1.