The installation of sysutils/upower somehow lacks installation to 'upowerd', which is also not on the system after installation
Using a script that triggers upower, the output is
(upower:8320): UPower-WARNING **: 19:46:24:256: Cannot connect to upowerd: Cannot connect: No such file or directory
FreeBSD 12.1-RELEASE-p8 GENERIC i386
Before upgrading from p7 to p8 all worked well.
*** This bug has been marked as a duplicate of bug 249349 ***
filed the bug in duplicate because of using the [<-] button in my browser...