Beacon is blinking constantly in scratch buffer and some other buffers (maybe since update to Emacs 27?).
I have beacon set up like this:
(use-package beacon
:ensure t
:config
(beacon-mode 1)
(setq beacon-color "Magenta"
beacon-blink-duration 0.01
beacon-blink-delay 0.2))
beacon-blink-duration and beacon-blink-delay appear not to cause this, the issue remains when set to defaults.