BatBoxes don't double or triple their storage anymore?

Back in 1.2.5, Batboxes when linked, can double their total stored power. A 40,000 Batbox would have 80,000 when linked to another via Copper Cables.

Now, it doesn't seem to do it anymore. What gives? I got this setup;

<- Machines [Low Voltage Solar Array]

And both are at 40,000, instead of 80,000.

Was this some kind of 'exploit' that was fixed?

Strange. I could had sworn I had over 40,000 units. Yet on my 1.2.5 one, it's the same thing.