Apple Account password... Arggh!

Years ago when I tried to log in to the Apple support forums, my account password was repeatedly rejected. I reset it. Later, I found that when asked for my account password for other purposes, the new one didn't work and the old one did. Apple had insisted that my account have two passwords, depending on what I wanted.
Today I migrated to an M4 Mini. Afterward, the old computer demanded that I log into my Apple account. It didn't do autofill, but I found it in Passwords.
Mail App wouldn't log in to my POP server. Spectrum told me to reach out to Apple. Apple's site required my account password to get any information. It rejected the password I'd used a few minutes ago. I opened Passwords to be sure I had it just right and found that my passwords hadn't migrated.
My old Mini seemed to have all my passwords but my Apple password, which had disappeared in the last few minutes! Fortunately I had a tested copy in print. Again and again it failed.
I clicked to say I'd forgotten my password. I changed my password, and the new one didn't work, either. The Safari popup clearly asked for my Apple Account Password, but finally I tried my user password for my Mac, and I got right in.
I hadn't known Apple even knew my user password. If they wanted it, why didn't they say so?
That was a lot of trouble to get to a couple of print tips. The first was to delete the Mail account and start a new one with the same server and address. Oh no, I'd been led to do that before and it meant a hassle with mail boxes.
The second should have been suggested first because it was so simple. Disable and re-enable the account. That didn't work, but disabling, restarting Mail, and re-enabling the account brought it online.
Meanwhile, after I changed my Apple Account password, Safari asked if I wanted to save it. Yes. Then I checked Passwords. It was not my new password, or the user password that got me in, but the old password.
Does Apple love to jerk the chains of Mac customers?