Hey there! Nice to meet you!
Please try accessing the subscription page on account.microsoft.com > Subscriptions using different devices and through Incognito or InPrivate browser. Then check if you can cancel the subscription.
If the issue persists, kindly reach out to Microsoft Billing Support for further assistance:
https://support.microsoft.com/home/contact?SourceApp=smc2&ContactUsExperienceEntryPointAssetId=S.HP.SmcContactUsLanding
Type "Cancel Subscription" > click "Get Help" > Scroll down to Sign in to Contact Support > Microsoft 365 and Office > Manage My Subscription > Confirm > Chat with a support agent in your web browser
Thank you for your understanding! Please let me know if you need anything else.
Best regards,
Darhyl