Default igb affinity

What is the difference in reference to the smp affinity from v19.xx to v22.xx? Why is the former at defaults for the most (which it should be totally up to the user to assign) vs the latter which doesn't seem to have an obvious configuration?

v19.xx runs inexplicably faster before any tweaks, which do show gains of 50% or more. v22.xx is rather slow and the affinity assignments look random.

irqbalance is not installed, just a clean ootb openwrt.

NAME="OpenWrt"
VERSION="22.03.4"
ID="openwrt"
ID_LIKE="lede openwrt"
PRETTY_NAME="OpenWrt 22.03.4"
VERSION_ID="22.03.4"
HOME_URL="https://openwrt.org/"
BUG_URL="https://bugs.openwrt.org/"
SUPPORT_URL="https://forum.openwrt.org/"
BUILD_ID="r20123-38ccc47687"
OPENWRT_BOARD="x86/64"
OPENWRT_ARCH="x86_64"
OPENWRT_TAINTS=""
OPENWRT_DEVICE_MANUFACTURER="OpenWrt"
OPENWRT_DEVICE_MANUFACTURER_URL="https://openwrt.org/"
OPENWRT_DEVICE_PRODUCT="Generic"
OPENWRT_DEVICE_REVISION="v0"
OPENWRT_RELEASE="OpenWrt 22.03.4 r20123-38ccc47687"

Linux OpenWrt 5.10.176 #0 SMP Sun Apr 9 12:27:46 2023 x86_64 GNU/Linux

Informational request to this post. I've tried researching many commits from different sources with no results. Please specify whether these are OpenWRT or Linux Kernel commits affecting the behavior of the releases. Thanks in advance.