My engine is a Ford/Pug production, and guess what? Yup, prone to split intake fanimolds. I thought I had one a couple of years ago, as it kept going into Restricted Perfromance all the time (a restart cures it, temporarily). Fortunately in my case, it was a split (plastic) throttle body, so that only took me 30 mins to fix, not 8+ hours on one of the manifolds.
Given that you've only had it 30s, I wouldn't mind betting thats why the previous owner got shot of it. Although hopefully on your engine, its a far simpler job than on mine.
I don't think JLR products deserve the reliability reputation they get. Yes, a BMW era 1990's Range Rover was a crock, more so that a BL era one. But since parting with BMW, I think quality and reliability has improved. A warning to all companies - good reputation is worth hanging on to at the expense of short term profit, bad reputation can take decades to change.
Although, JLR clearly need to change their bought-in engine manifolds, and also change their door latch provider

Hope it gets sorted quickly, and you can start to enjoy what is a nice place to be when cruising around.