I’m a size M guy, everything from head to toe is M. If M doesn’t fit, I will try S, but most of the time that is too small, so I just skip that fit or brand. Sometimes the size difference is so ridiculous it might as well be two different shirts. One time I tried a polo in M and it looked like an oversized 90s hip‑hop shirt on me so I tried the S and it was so tight it looked like swimwear lol.
I did the same! It was not jeans but pants that is supposed to look like they are a bit more formal but are more comfortable. From the website did I just pick 3 different colors of the same size but they all fit so differently, and one pair had much thicker fabric, felt more like they went “close enough” and called it a day lol