As of September 11th, 2017, Capital One Bank has migrated their Capital One 360 accounts to their Capital One Bank site.
Bank accounts that were linked under 'Capital One 360' before September 11th, 2017, have been migrated to 'Capital One – Bank' and should continue to update as expected.
If you are trying to link a new Capital One 360 account, please search for 'Capital One – Bank' to link your account in Personal Capital.
Once you add the new accounts, be sure to mark the "old" 360 accounts as closed. You can read more about how to close an account here: How To Mark An Account As Closed In Personal Capital.