Permission denied when checking mounts

Hello everyone!
I’m trying to make a call to the “/v1/sys/mounts” endpoint with the admin token I got from the vault (the token has root permission, I’ve checked it in lookup-self, it has the hcp_root policy). However I keep getting the same error: “1 error occurred:\n\t* permission denied\n\n”.
I’ve made sure that the header is not misspelled by the way.
Anyone has any idea of what is happening?

Thanks in advance!