I haven't be able to use the function "insert comment" because I don't find the option in my excel, however I have used it many times but now It don't appear in my options. Please a I need help, I use this function frecuently in my job.
@AngieM- I just came across this issue with a customer of mine and reported it as a BUG to Microsoft. They confirmed my findings as well as my temporary solution and it has been submitted to development to be corrected. If I had to guess you likely have an Enterprise License (possible an E3 plan). Your installation of Office365 shows up as ProPlus in your Programs and Features section of Windows. Uninstall your current installation of Office365 from your computer. Next, Login as a user in a New In Private Window in Edge that has a Business Premium License for Office 365 and download Office365 from their subscription. Once the installation is completed you will still be signed into office with your enterprise login but running the Business-en version of Office 365. Go to Excel and confirm the Insert Comment functionality is restored. Please reply back and confirm if all is working correctly an be on the lookout for a permanent fix from development on the ProPlus installation.