The basic principles:
https://en.wikipedia.org/wiki/Dark_pattern
A larger breakdown:
https://www.shopify.com/partners/blog/dark-patterns
For example, the sign-in difficulties shown above:
https://social.coop/@atomicpoet@mastodon.social/109473890149969038
They may just be related to a design issue, but they can also be attributed to potential bait'n'switch tactics.
( Yes, i did read the T&C's as well as the Privacy Policy, but those include the right for them to be changed unilaterally by your company. )