Thank you for all the responses. Before receiving any responses, I tried switching back to unstable branch and updating and downgrading using -Syyuu. The response on unstable was that there were no updates to perform and that the downgrade could not be perfromed because of something to do with Kwin. I tried switching back and forth a couple times (without downgrading) and there was no change. When on unstable branch, I tried to install the plasma-x11-session and kept receiving the message that it could not be found. I checked pacman-mirrors -G and the response was unstable.
I also tried starting wayland from TTY as suggested and there was an error code of 255.
The journalctl warnings scrolled for quite awhile and what I could read had to to do with different items in plasma not starting.
Then, this morning, I tried to run updates again to unstable and there was about 1 GiB of them. After installing them, everything started as usual; except much faster than in the past. I don’t see the spinning KDE gear any longer because it just opens. Also, I could install plasma-x11-session.
I must have been doing something wrong; however, I did the very same things, today, as I did before posting, which were mostly following these instructions for switching branches and [root tip] [How To] Update Manjaro the smart way for updating in TTY.
Also, the settings I referred to for not logging on are in SDDM Behavior. I apologize if that was confusing. That works now also.
I think I will just stay on unstable, now. I do my work on a desktop on stable branch and use this machine (a laptop) for backup and testing; and to install updates first as a precaution.
I suppose (for those answering) this is an unsatisying resolution since I cannot point to the exact issue of what I did wrong. Nonetheless, for me, I am very grateful for this forum and those who take the time to respond; because it can be a very frustrating and sort of lonely feeling trying to figure out why my machine won’t work any longer. I had always wanted to try linux but could never find a version that I felt confident of, until someone on a different forum made a passing comment concerning Manjaro. Now, I’ve come to depend on Manjaro and would not want to change to another OS. So, thank you for all the help and information.