You have caught the issue
compare checksum: c79a65da525c5985f1dcd3afda1796a2695822b3994b2e38aa28e9ed79a8ac30 vs 123347885d7fd2cdd0cfe39f23292d76770f9be926e5162614f12c3ecafc3d9c
This checksum mismatch has been a frequent bug. https://gitlab.e.foundation/e/backlog/-/issues/7225 https://gitlab.e.foundation/e/backlog/-/issues/7144. As I understand it there is a fix in v0.20.1 but not the full final fix which is hoped for in version 0.21.
First have you got latest version Easy Installer? Version 0.20.1 shows in the Easy Installer window title bar. Forum workarounds can be searched from Easy Installer + easy-installer.
This workaround is maybe worth a try Installer stops after downloading, no error or acknowledgement just a "Try again" button - #7 by lma.