I found a good article (https://itsfoss.com/ubuntu-keyring/) on keyrings. The most important thing I learned from it is that if you have automatic login, you will get a keyring window requesting your password the first time you open a browser or other app that requires a password. I don't know if this is try on all desktop environments, but it definitely is with KDE. This might be related to the annoyance I had anytime I ran Plasma in Ubuntu, although I don't use automatic login. Because I don't autolog, I still don't understand why I was getting this, but it is one of my greatest annoyances with KDE/Plasma. Having said that, I rarely if ever get a keyring window in my OpenSUSE installation (no autologin).
I'm not sure about the autologin thing. I've always used a password to login to my box and have gotten the keyring message whenever I use something that requires a password (if I remember correctly).
However, in Plasma, it doesn't have to annoy you, Fox, all you need to do is to use a blank password instead of hitting cancel. When you do that, it'll tell you that doing so will mean your passwords won't be saved securely and if you're okay with that. Once you say yes, it will never come up again. I've been using Plasma for at least a year now and never see it. Now, if I remember correctly, you have to actually click on the fields to enter the master password and don't put anything in them and then click OK for it to work. If that doesn't work for whatever reason, just bring up Kwallet and then choose to disable it in the options.