I ordered a Boden “Abigail” dress in the same size and “Long” fit option as a similar style I have , which was the fit I needed to get the hem to fall below knee.
When it arrived and I tried it on it is a couple of inches ABOVE the knee, but clearly labeled “ L”. It’s barely 37” long. I checked their measurement chart and it should be almost 41”. It’s 3-4 “ shorter than my other “Long” Boden dress.

Tomorrow I’ll try to chat with Customer Service to see this seems hopefully a labeling error/ fluke and the Long size is supposed to be as in the chart, so can be replaced. I would be so bummed if they’ve actually shortened the fits!