You need to cancel always the extension (12 months) of your work permit, even when you finished the work with the end date of validity of your extension.
If you enter before 23 october 2025, you will stamped in for 12 months or max the validity of your health insurance (need the special form).
Be aware that you will loose your multi-entry on october 23rd. You need to buy re-entry stamp when leaving on the new 12 months (or validity of your health insurance) stamp.