After clocking into an entry (org-agenda-clock-in) from an agenda buffer (such as org-agenda-list), the entry is highlighted with a face (org-agenda-clocking). When the entry is no longer clocked in, e.g., by clocking out or marking it DONE, the org-agenda-clocking face is normally removed.
However, org-agenda-clock-cancel is the exception, as it doesn't update the clocking entry's appearance. Pressing r (org-agenda-redo) fixes the appearance. I suspect org-agenda-clock-cancel just needs to call org-agenda-unmark-clocking-task. Emacs : GNU Emacs 29.2 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo version 1.18.0, Xaw3d scroll bars) Package: Org mode version 9.6.15 (release_9.6.15 @ /nix/store/5hl68vr85cagmwaycqy652r2g2isjcyq-emacs-29.2/share/emacs/29.2/lisp/org/)
