Why is Nvidia repo failing for 15.4? [PROTOCOL_ERROR (err 1)]?

All, On a couple of zypper refresh attempts lately, I receive: Problem retrieving files from 'nvidia'. Download (curl) error for 'https://download.nvidia.com/opensuse/leap/15.4/repodata/repomd.xml': Error code: Curl error 92 Error message: HTTP/2 stream 5 was not closed cleanly: PROTOCOL_ERROR (err 1) History: - Giving up after 3 attempts. Is this a known issue, or something spurious on my end? -- David C. Rankin, J.D.,P.E.