My macOS Monterey keeps losing window focus
My Mac Pro (Late 2013) running Monterey has become unstable. Open windows of various apps keep losing focus.
Mac Pro, 12.7
I have macOS Monterey 12.7.6 and do not experience what you have mentioned. Consider what you may have installed just before this issue developed.
The operating system does not feature a pointer-driven automatic application focus. One must click in the Finder, or any open application window to redirect keyboard and pointer focus there. Or by using the cmd+Tab interface, cycle through the open applications.
One lingering issue has been if the Terminal window is opened and you then launch another application, the pointer and keyboard focus are stuck on the Terminal until one changes it. I submitted a bug report to Apple even before Monterey and it remains unfixed in Sequoia.