I am facing attached an error while browse directory on 50070 port after kerberos configuration.
Permission denied when trying to open /webhdfs/v1/?op=LISTSTATUS: GSSException: No valid credentials provided (Mechanism level: Failed to find any Kerberos credentails)
Do you have Authentication required for the UIs enabled (Enable Kerberos Authentication for HTTP Web-Consoles)? I would try enabling it to ensure that you are providing the tgt to the browser to even access the NN UI. And from there it should pass it along when it tries to access WebHDFS.
You can also try from the command line using curl and --negioate to access WebHDFS and HttpFS just to make sure they are working correctly independintly of the client browser.
This is for an older version but the details have not changed. Read it to configure your browser to negiotiate for authentication.