Same here... but the frequency is 500 Mhz.
Usually it happens after a recharge.

After this, very often the battery drain increases about 3 times until next shutdown.

I have verified everything, but also creating a dbus script executed at the end of charge to fix the min max limits of cpu clock the issue remains.
Often, in locked mode i can find:
min=125
max=250
current frequency=500 ?!?!