We are running Moodle 3.9.2 and this issue started happening after we upgraded from version 3.6.9 a couple weeks ago. We are currently running 3 different instances of Moodle with the same version and it is happening on all of them. I have tested within the Boost theme and the Snap theme as well, but the issue continues.
When an assignment activity has additional files added in the settings, the "Save changes" button is disabled when students try to add a submission. This issue occurs only when accessing the assignment via the webpage, but seems to work fine through the mobile app.
Any suggestions would be appreciated to help figure this out.
1. Create an assignment activity and attach a file to the additional files area.
2. Log in as a student.
3. Access the assignment created from step one by clicking on it.
4. Click the "Add submission" button.