The plugin supports 3D secure payment.
Go to the Advanced settings menu of the plugin and try enabling the following feature:
Disable 3D Secure Iframe
This is be helpful on some server configurations.
Next, enable the following debug logging option and do a transaction. It can give additional clues about the issue:
Using the Debug Log to Solve Transaction Related Issues on a Site
Also, make sure the stripe subscription addon is updated to the latest.