I eventually learned that there's a 'correct way up' for USB A cables. The two small holes should be on top.
Tragically not all power adapters get this right, even for name brands. My ability to get the cable right first time still isn't much better than 50%!
Delighted to see that TOML has released a new version! TOML is overall a great standard but I understand they had limited people with the power to cut a new release.