What is the error that shows up next to the "Failed" message? Some Azure products cannot be transferred and if that's the case you need to remove those before transferring. Disabled subscriptions also can't be transferred
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/mpa-request-ownership
Are you able to confirm in the other directory that the subscription transfer has not completed? If you are part of the directory and have proper rights then you should be able to see the subscription once you switch to that directory using the "switch directory" option.
Does your company have enterprise agreement.? If you do, then the Azure EA admin can also change the directory-subscription associations from the EA portal.
If you still know the subscription ID then we can still activate a support request if none of the above works.
Also, if you no longer have access to the tenant itself, you'll need to either reach out to a global admin to help you get back in OR, if there are no additional global admins on the tenant, reach out to the Azure Data Protection team (866-807-5850).