Weird purple/flare-like text on booting up

Not long ago, my computer started doing this on boot.

I have done some testing, and it seems to be doing this only on first boot (when computer hasn't been used prior), or when doing updates (?). Other attemps at recreating it has shown nothing.

Aside from that, everything seems to be working fine.

Video: https://youtube.com/shorts/pVByruSiZTk?feature=share