Same issue here. Had it for 2 years and still unresolved. Lotus dealer couldn't figure it out either. Well, they fixed it once...it was a bad ground on the compressor (they said). The 2nd time they said they were going to have to pull the front clam off to inspect further and that's where we left it.
I have done everything myself to try and troubleshoot. I inspected the flap and found it's working as it should. I found the temperature probe was pressed hard into the condensor radiator so I pulled it back a little..no change. I even changed out the AC control relay, but it didn't help.
My suspicion is the compressor is bad. I think it kicks on because there is a noticeable drop in engine idle when the AC button is pushed, but this might not be a good method to verify the clutch is in fact engaging. Most modern cars automatically adjust idle when the AC button is pushed regardless if the compressor is working or not. My next step was to have someone put their head next to the compressor and listen closely to hear it engage.
Either way, I am literally out of options right now and it seems the ONLY thing I haven't tried is swapping in a new, ridiculously overpriced, compressor. I'm thinking of using a similar Toyota unit (with the slightly larger pulley) to save a little coin. I hear it works just was well.
My fear is that the problem will still exist and that I'll end up having to spend $2000 at the dealership anyways.
F**K this problem seriously.