I'm a little confused, is "en_windows_server_2019_updated_dec_2019_x64_dvd_16a7884e.iso" are latest LTSC version out there ?
If I'm not mistaken this is the latest server 2019 version: 586E928C724DFB2AD9506AEFE85E0EE97A91CF56 *en_windows_server_2019_updated_april_2020_x64_dvd_12d6dc63.iso Take a look at GezoeSloog signature to grab a copy of it. Note: server 2019 is windows build 17763
He is correct Released: 21/04/2020 SHA256: DB8A91E451DB99193D6E371A9668C486D5B1013DBF02ABDC5D301BA06F29341B File name: en_windows_server_2019_updated_april_2020_x64_dvd_12d6dc63.iso
Server 2019 got refresh ISOs in April 2020, Enterprise 2019 LTSC got it's latest refresh ISO march 2019 (17763.316).