We understand that your students may be having difficulty submitting assignments on Microsoft Classroom. Here are some steps that you can take to try and troubleshoot the issue:

1. Check to see that your students are using the correct web browser.
2. Ensure that your students have the correct version of Microsoft Classroom installed.
3. Review the class settings to see if there are any changes that may have occurred which are preventing students from submitting assignments.
4. Restart the browser or uninstall and reinstall the Microsoft Classroom application.