Zypper interrupted preload always redownload from start

Seems same as usual.
First unintended network interrupt, without --download in-advance.

Preloading: vscodium-1.105.06808-x86_64.rpm [HTTP/2 stream 1 was not closed cleanly: PROTOCOL_ERROR (err 1)]
Preload finished. [files missing (141.4 KiB/s) ] ..............................[done]
Installation has completed with error.

And to reproduce --download in-advance parameter with intended connection reset (because my vpn software sometimes need to reset the connection if i need to change the server.)

Preloading: vscodium-1.105.06808-x86_64.rpm [OpenSSL SSL_read: OpenSSL/3.5.3: error:0A000126:SSL routines::unexpected eof while reading, errno 0]
Preload finished. [files missing (878.9 KiB/s) ] ...............................[done]
Installation has completed with error.

Yes seems my wording wrong. It is redownload the whole package/rpm which are interrupted. Because nvidia driver download 3 iirc package from their repo, and the network not quite stable to their repo, it’s those 3 which also not cached in my computer. It’s not problematic for other which are finished and cached.

running ls -la /var/cache/zypp/packages/gitlab.com_paulcarroty_vscodium_repo/.preload/ after error above, seems no contain anything, even parent dir.

Does zypper allow resume partial downloaded packages?