Yes, I restarted, but that did not solve the problem. I had to manually set back the 3 contacts that have messed up info. As I mentioned in another post, the mess happened right after I downloaded, tried and then immediately uninstalled, one after the other, 3 different Dialers apps (Drupe, Simple Contacts and Truecaller) and also 2 different Calendars. Maybe this caused the problem with my contact list.
Right now, all is back to normal, but I would like to understand why it happened.
My best guess as to what happened is...
One or more of those apps you installed (possibly TrueCaller, but maybe one (or more) of the others) added some contacts, and jumbled some info as you discovered.
TrueCaller uses an online data base for contacts and calls to block, and it disrupted multiple contacts of my own.
It even kept identifying me by the name of Kevin- which is not my name- but is the name of the last person to have my cellphone number.
So, when you uninstalled these apps, how exactly did you do that?
Did you just uninstall them, or did you delete the app data first?
Sometimes (often, you could say) files, ads, and other unwanted info is stored in files not included in an app's data.
So when you just uninstall, some of that data can be left behind on your device.
That is why, even though it is less convenient, it is advisable to always delete an app's data first and then uninstall it.
In fact, some people have even reinstalled an unwanted app, run the app, then gone back to delete the app data and then uninstall the app.
This method could possibly have saved you the 10 hours of PITA frustration.
I know how aggrevating that must have been.