C5 W3 Trigger Word Detection. Can't save notebook

I’ve completed all exercises successfully but when I reached the last exercise the “save and checkpoint” button and the “ctrl-s” shortcut don’t seem to be saving the notebook. When I refresh my code for the fifth exercise is not saved which results in a 20% deduction on the assignment as exercise 5 is incomplete. How can I save all changes to the notebook so I can get the grade I deserve.

Hey @Farida_Yasser,
Welcome to the community. That’s indeed strange. Did you try restarting your kernel and saving the changes? Also, can you please ensure that you can connect to the kernel and run the assignment in Coursera labs from the beginning to the end, without any issue?