This worked for me.
Because we cannot install software on our computers, most students did not hit "Access" when signing up since we cannot download or install software on our machines.
To most common issue was the last one. To fix it, I had the students do the link provided again: https://www.autodesk.com/education/edu-software/overview
When we got to the "Your educational access to Autodesk is valid through ...(1 year) . This is where most of them stopped.
To complete the process, we did the following steps:
Go to Fusion 360 and hit "Get Product"
When the next screen comes up, click "access"
Even if you do not have access to install, it is probably still a good idea to start the download anyway - seems to help.
The students were them able to have their access, no problem.
Hope that this additional details helps.
Students should be able to log in after that, mine were able to right away.
This is assuming that you have previously done all of the steps (letter, etc.)
