Somehow my Software Center window has become as wide as both of my monitors, and although I can make it even wider, I can't make the window narrower.
I am getting this too. It might be related to removing the snap plugin, as it didn't seem to have this problem until I removed snapd and the plugin. The number of dots under the displayed image keeps increasing each time the app is started, making the window wider. I've tried purging and reinstalling the package with no success. I did find a workaround:
killall gnome-software # just in case it's still running rm -rf ~/.local/share/gnome-software
So far I've opened and closed the app several times and the size has remained constant. Not sure that it's a permanent solution though. I suspect there is a bug.