I've had this issue intermittently over the years but it does not appear to be transient this time.
All downloads from downloads.openwrt.org fail but not from Github.
# opkg update
Downloading https://raw.githubusercontent.com/stangri/openwrt-repo/master/Packages.gz
Updated list of available packages in /var/opkg-lists/stangri_repo
Downloading https://raw.githubusercontent.com/stangri/openwrt-repo/master/Packages.sig
Signature check passed.
Downloading https://downloads.openwrt.org/releases/18.06.5/targets/x86/64/packages/Packages.gz
*** Failed to download the package list from https://downloads.openwrt.org/releases/18.06.5/targets/x86/64/packages/Packages.gz
Downloading https://downloads.openwrt.org/releases/18.06.5/packages/x86_64/base/Packages.gz
Tried testing with curl and I get:
# curl -k -vv https://downloads.openwrt.org/releases/18.06.5/targets/x86/64/packages/Packages.gz
* ssl_handshake returned - mbedTLS: (-0x0050) NET - Connection was reset by peer
curl: (35) ssl_handshake returned - mbedTLS: (-0x0050) NET - Connection was reset by peer
The thing that confounds me is that a browser behind the same openwrt router can download the packages fine. What am I missing here?