Depends on geo I think. CX bikes tend to be a larger frame size number than you might expect from a road perspective. If I was running into a conflict of my preconceptions and the company’s sizing chart, I’d go sit on one and then have a hard think about it. I bought a 58 Cotic X a few years ago because I thought I was right on the crossover between 56 and 58 and the 56 looked like it was running a lot of post. Result was a bike that worked well as a stretched out tootler but wasn’t very sprinty fast.
When I was looking for a replacement I spotted a 54 Crosslight5T and tried it anyway, expecting it to be silly small and had an ‘it fits!’ moment. I’m 2cm taller at 178 than the recommended range on the size chart, but it’s perfect for me.