Flickering Rainbow Screen glitch when shutting down

https://discussions.apple.com/thread/250874875?answerId=251677735022#251677735022

linked to the post by tathos and answered by the community.

I would like to add that this could also be hardware related. I noted (tried several times) that when i turn my mbp off (2019 entry level) with the AC source plugged in, rainbow flickers are present, but when i turn it off unplugged, it shuts down normally.