Hi Matthew Wotring,
We appreciate your engagement through the Microsoft Q&A forum.
We regret to learn about the challenges you're facing in accessing the sandbox.
We've conducted multiple attempts from our end and successfully accessed the sandbox. We've attached a screenshot for your reference.
Meanwhile, please consider trying the troubleshooting steps outlined below for this issue:
Step 1: Sign out from all tabs in your current browser and clear the cache files. Then, attempt to log in again using your Learn ID credentials.
Step 2: Sign out from the current browser session and try logging in again using an incognito window or private browsing mode.
Step 3: Switch to a different browser and attempt to log in again.
Step 4: Log in with a new personal email account into the learning path using a completely new browser and verify.
Troubleshooting common training issues in Microsoft Learn: https://learn.microsoft.com/en-us/training/support/troubleshooting
If you are still running into issues, kindly attach the screenshots of the error you are getting. We will glad to assist you.
If the information is helpful, please accept the answer by clicking the "Upvote" and "Accept Answer" on the post.
Thank you.