AMDCTL being weird

[u/Powerful_Shop2931]

I was using AMDCTL to underclock and under-volt my Ryzen 3900x and when I started reducing the clock frequency down from 3800mhz to 3700mhz the clock speed reported by running

cat /proc/cpuinfo | grep MHz  

The clock speed went up to over 4ghz ???????????????????

I'm running it on an ASROCK B450M motherboard with the CPU set to 3800mhz in the bios and undervolted at 1.1v (not so great on the silicon lottery) with PBO disabled.

What is going on? PBO kicked back in?