Unable to see SignUpSignIn and SignIn user flows in Azure AD B2C portal (401 error on direct link)

I have an Azure AD B2C tenant and I created SignUpSignIn and SignIn built-in user flows. They are working fine, but now they no longer appear in the User flows page in the portal.

When I try to access them via a direct link, I get this error:

{"sessionId":"adf14e088af4494d9d17b3047aef39ef",
 "subscriptionId":"",
 "resourceGroup":"",
 "errorCode":"401",
 "resourceName":"",
 "details":"You don't seem to have permission to view this page."}

I am a Global Administrator in the b2c directory, how to resolve this issue