Training: Instruction to develop new skills.
Hello Nguyen
Thank you for the detailed information. It sounds like you've already done the sensible troubleshooting, so I wouldn't keep retrying the renewal for now.
First up lets ensure you are in the correct directory - Go to >Azure Portal → account menu → Switch directory and make sure you're viewing the directory associated with your student account. You can also check the Azure Education Pane for the subscription. A similar Microsoft Q&A case used these as the initial checks when the student subscription wasn't visible. [learn.microsoft.com]
If it's still missing after you have verified the above check, then an account level review will be needed. Microsoft Learn directs Azure for Students users with subscription issues to create a support request. I have attached the link here for you -
Definitely keep that Session ID, timestamp and screenshots on hand for support.
Another small thing I noticed: the question is tagged Artifact Signing, but this is really an Azure for Students/subscription issue. I suggest changing the tag if possible - this ensures your issue is seen and responded to by the right team and saves you from being redirected.
Hope this helps, all the best with your learning.