Brightness 100% when connect or disconnect charger

From: Dr. Amr Osman <dr3mro_at_gmail.com>
Date: Wed, 08 Nov 2023 22:33:31 UTC 
Hello,
I have installed freeBSD 14rc4 on Lenovo Thinkpad x270 and xfce desktop and
when I
1) connect the charger
2) disconnect the charger
3) resume from suspend
The LCD brightness is 100% which is really disturbing specially when I am
in dark room

hw.acpi.video.lcd0.economy: 20
hw.acpi.video.lcd0.fullpower: 30
I have loaded acpi_video and acpi_ibm
and if I tried to adjust brightness it goes suddenly from 100 to 20 if I
press fn +f5/f6

What can I do to fix this issue?
Thank You
Dr. Amr Osman