I also experienced this bug just now on FreeBSD 14.1-STABLE stable/14-n268491-09d61b28a00a GENERIC amd64 on 11th Gen Intel(R) Core(TM) i7-1185G7 @ 3.00GHz (2995.20-MHz K8-class CPU) after I upgraded several parts, including my 55 Wh battery to 61 Wh battery. I was already on BIOS 3.20 when this happened. Doing your suggestion fixed my issue. Thank you!
We can see the before and after speeds:
sysctl -a | grep dev.cpu.[0-9] | grep freq: | sort -n
Before
--------
dev.cpu.0.freq: 398
dev.cpu.1.freq: 398
dev.cpu.2.freq: 398
dev.cpu.3.freq: 398
dev.cpu.4.freq: 398
dev.cpu.5.freq: 398
dev.cpu.6.freq: 398
dev.cpu.7.freq: 398
After
-------
dev.cpu.0.freq: 2492
dev.cpu.1.freq: 2839
dev.cpu.2.freq: 2549
dev.cpu.3.freq: 2839
dev.cpu.4.freq: 2609
dev.cpu.5.freq: 2833
dev.cpu.6.freq: 3238
dev.cpu.7.freq: 2692