Accessing the Microsoft Learn Sandbox but it keeps asking me to verify my account via puzzle

Question

I'm in the section 'Exercise - Explore the Learn sandbox' of the module 'Describe the core architectural components of Azure' of Learn. After accepting terms and conditions to use the sandbox service and verifying my account using a puzzle, it keeps me asking to 'Verify your account' as you can see:

I tried several times to verify again the account trough the puzzle. I insured that I inserted a verified email and phone number. I insured that I'm accessing using a trusted pc. I cleared the cache and the cookies. I signed out and the signed in. I signed in with another account after created it then I tried to access from incognito. I changed browser and It still keeps me asking to 'Verify your account'. What causes this problem? Thank you.