I am also observing this on Opensuse Tumbleweed, on the latest kernel (6.6.11-1-default). All cores are stuck at a maximum of 544 MHz. To get the system unstuck (in Linux), I just found the workaround described here: [SOLVED] [FW 13 AMD 7840U] Did kernels >=6.6.7 make your system/touchpad/mouse laggy? - #12 by bikefrivolously
For easy reference here: To unlock the core frequencies, toggle the scaling governor like so
sudo cpupower frequency-set -g performance && sudo cpupower frequency-set -g powersave
EDIT: I’m also on Bios 3.03