opam install Curl failed - ocaml

Question

newbie question:
I have opam version 2.0.5 installed on windows 10 (using cygwin).
I tried to opam install utop
all but 3 out of the 22 packages installed fine, so i don't think it is network issues.
What can I do about the 3 that don't install, and why is this happening? (I have tried on two seperate days).
<><> Gathering sources ><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
[camomile.1.0.2] found in cache
[charInfo_width.1.1.0] found in cache
[cppo.1.6.6] found in cache
[dune.2.1.2] found in cache
[dune-configurator.2.1.2] found in cache
[dune-private-libs.2.1.2] found in cache
[lambda-term.2.0.3] found in cache
[lwt.5.1.1] found in cache
[lwt_log.1.1.1] found in cache
[lwt_react.1.1.3] found in cache
[mmap.1.1.0] found in cache
[ocamlbuild.0.14.0] found in cache
[ocplib-endian.1.0] found in cache
[result.1.4] found in cache
[WARNING] ocamlfind.1.8.1: download of
http://download.camlcity.org/download/findlib-1.8.1.tar.gz failed
(http://download.camlcity.org/download/findlib-1.8.1.tar.gz (Curl
failed: "D:\\cygwin64\\bin\\curl.exe --write-out %{http_code}\\n
--retry 3 --retry-delay 2 --user-agent opam/2.0.5 -L -o
D:/cygwin64/home/ysg4206/.opam/ocaml-variants.4.07.1+mingw64c/.opam-sw
itch/sources/ocamlfind.1.8.1/findlib-1.8.1.tar.gz.part
http://download.camlcity.org/download/findlib-1.8.1.tar.gz" exited
with code 28)), trying mirror
[utop.2.4.3] found in cachep] [topkg.1.0.1: http]
Processing 21/22: [ocamlfind.1.8.1: http] [topkg.1.0.1: htt
[zed.2.0.4] found in cache
[ERROR] The sources of the following couldn't be obtained, aborting:
- ocamlfind.1.8.1: Curl failed
- react.1.2.1: Curl failed
- topkg.1.0.1: Curl failed
ysg4206#YSG4206 ~
$ opam --version
2.0.5