Wireless keyboard not working after reboot Catalina

Just recently, possible after automatic install of macOS Supplemental Update build 19A602, my wireless keyboard and Magic Mouse are not working. I can restore the keyboard by plugging in the USB charging cable and then unplugging and it works again. The Mouse I have to plug in a wired mouse and fiddle with the Bluetooth preferences to get the connection to the Magic Mouse restored, then I can use it again. I tried booting into Safe Mode, but that did not change the behavior. What to try next?