Woe was me. Details on request. Much was not working, across several programs, with keyboard input. This morning all my KM "insert" macros failed. The macros executed, as I could tell by watching them rise to the top of the KM list sorted MRU, but inserted nothing visible. 4 hours and 11 minutes later I not only had my "insert" macros back, I had resolved a tetchy issue with LaunchBar's "insta-send" and likely a dozen other errant legs (bugs without bodies).
The bug of bugs? Accessibility Permissions. Inestimable Peter's bug-shooting guide here was the first (perforce the only, as it worked) useful help I found online. Thank you @peternlewis 
. Deleting the items in the accessibility list and then letting each program re-install them resolved all issues. (Safe Mode did not.) Rebooting is no longer a tarantella between System Settings and application alerts. LaunchBar's "insta-Send", which I discovered I use a lot, works for the first time in months. My computer house is quiet; programs work. G'night all.
MacOs 13.2.x