Ben Greiner wrote:

For python3-pyside2 you have to wait for the next snapshot: 
https://build.opensuse.org/request/show/1093899

Thanks for the explanation. I probably will wait but am afraid that it won't fix the many other errors not related to python310 I'm getting, like:
 Solution 3: remove lock to allow removal of libQt5DBus5-5.15.9+kde154-1.3.x86_64

I'm sorry, but I don't understand. The first mention 
of python310-qt5-5.15.9-1.5.x86_64 is in the conflict regarding python310-matplotlib-qt5-3.6.3-2.1.x86_64. The full text is:

```
Problem: the installed python310-matplotlib-qt5-3.6.3-2.1.x86_64 requires 'python310-qt5', but this requirement cannot be provided
  deleted providers: python310-qt5-5.15.9-1.5.x86_64
not installable providers: python310-qt5-5.15.9-2.3.x86_64[download.opensuse.org-oss]
 Solution 1: Following actions will be done:
  remove lock to allow removal of python310-matplotlib-qt5-3.6.3-2.1.x86_64
  deinstallation of python310-qt5-5.15.9-1.5.x86_64
  deinstallation of cura-4.13.1-2.3.noarch
 Solution 2: keep obsolete python310-qt5-5.15.9-1.5.x86_64
 Solution 3: remove lock to allow removal of libQt5Core5-5.15.9+kde154-1.3.x86_64

 Solution 4: break python310-matplotlib-qt5-3.6.3-2.1.x86_64 by ignoring some of its dependencies

Choose from above solutions by number or skip, retry or cancel [1/2/3/4/s/r/c/d/?] (c): 2
```

I didn't want solution 1 because I don't want to lose "cura". But again, this was a "--dry-run". If I was doing it with "--dry-run" and kept python310-qt5-5.15.9-1.5.x86_64, would some of the other conflicts resolve themselves?

Again, what's my best way out of this? I'd prefer not to have to remove a large number of packages, do the "dup", and then reinstall them, but if that's the only solution I guess I'll have to. Or, even worse, get the latest ISO and reinstall Tumbleweed from scratch and then add all my desired packages (hundreds) again.