--- a/.emacs-my	Sat Dec 24 21:43:47 2022 +0200
+++ b/.emacs-my	Thu Feb 02 02:14:23 2023 +0200
@@ -2743,7 +2743,9 @@
 ;; Since 27.1 it is enabled during font-lock. Need to disable explicitly.
 (setq diff-refine nil)
 ;; https://emacs.stackexchange.com/questions/61760/lags-when-navigating-vc-root-diff-buffer/
-(setq diff-font-lock-syntax 'hunk-only)
+;; Disable the feature as it visits files from Git and this is extremely slow in Cygwin+antivirus.
+;; nil / t / hunk-only / hunk-also
+(setq diff-font-lock-syntax 'nil)
 
 (when (and window-system (< emacs-major-version 26))
   (my--eval-after-load diff-mode