Horse bed can't call ranch hand off the grid

I'm playing off-the-grid using the 2 Olde Mill Lane lot in Henford-On-Bagley. I am generating power using the wind turbines and solar panels from Eco Living and I have a surplus stored if I look at Show Bills Information on the letter box.

I want to get a horse for my sims, so I bought and selected the horse bed. Under the Call Ranch Animal Exchange menu, both the Rescue and Buy Horse options are greyed out with the tooltip that "the internet doesn't work off the grid". By comparison, the phone and laptop fully work. On the phone, I can use the Home / Call Ranch Animal Exchange option using the phone. The Rescue and Buy Horse options don't do anything (the icon just drops from the queue, but the Buy Mini Goats And Sheep work as expected, both on the phone and the Horse Bed. 

I normally use mods, but I've started a no-mods/no-cc save, waited until I generated a surplus and tried again. It was still the same. I have all expansion packs, game packs and stuff packs, but only a handful of kits.