Mmm, I mean it looks like an ACPI problem, like bad tables. You might update you BIOS if an update is available.
You could try running vmstat -i see if that shows a device with high interrupt rates.
You can also try booting in verbose mode and see if that shows any useful ACPI errors. Interrupt the boot at the boot loader and then enter boot -v.
See also: https://www.freebsd.org/cgi/man.cgi?query=acpi&apropos=0&sektion=4&manpath=FreeBSD+11.2-RELEASE&arch=default&format=html
Steve