Go to Setttings > LSP Client > Format on save If it is unchecked and you check it, it starts applying. When it is checked and you uncheck it, formatting is still applied on save until you restart Kate.
A possibly relevant merge request was started @ https://invent.kde.org/utilities/kate/-/merge_requests/1925
Git commit b3aede291bde73bef7a65b2bdd095f5509dcc958 by Christoph Cullmann, on behalf of Waqar Ahmed. Committed on 22/10/2025 at 20:22. Pushed by cullmann into branch 'master'. lsp: clear formatOnSave connection in updateState Otherwise we remain connected even if formatOnSave was disabled M +8 -4 addons/lspclient/lspclientpluginview.cpp https://invent.kde.org/utilities/kate/-/commit/b3aede291bde73bef7a65b2bdd095f5509dcc958
Git commit 902c288fa177759747f5b338273c04373877b2d4 by Waqar Ahmed. Committed on 31/10/2025 at 06:27. Pushed by waqar into branch 'release/25.08'. lsp: clear formatOnSave connection in updateState Otherwise we remain connected even if formatOnSave was disabled (cherry picked from commit b3aede291bde73bef7a65b2bdd095f5509dcc958) M +8 -4 addons/lspclient/lspclientpluginview.cpp https://invent.kde.org/utilities/kate/-/commit/902c288fa177759747f5b338273c04373877b2d4