I have the same problem on my desktop with image-builder. It is stuck here and never downloads.
I don't have IPv6 on my PC. It is disabled completely with sysctl. I think opkg is somehow hardcoded to use IPv6.
Package list missing or not up-to-date, generating it.
Building package index...
.......
Downloading https://downloads.openwrt.org/releases/22.03.3/packages/mipsel_24kc/base/Packages.gz
Your problem is likely different, please do not mix things up.
If you have just the small built-in wget replacement uclient-fetch, it does prefer IPv6 over IPv4 if IPv6 addressing and DNS is found, and has no good fallback to IPv4.
But if you install the full GNU wget (wget-ssl), you get a proper fallback.
OpenWrt SNAPSHOT, r22199-1f53fa2b83
-----------------------------------------------------
root@router5:~# which wget
/usr/bin/wget
root@router5:~# wget --version
GNU Wget 1.21.3 built on linux-gnu.
Note that if you explicitly disable IPv6 for some reason, you should also disable IPv6 address resolving, or you may end up with problem in some situations.
I moved this to a separate thread, as your download problems from PC (with intentionally disabled IPv6) do not have much common with the router's wget 4 errors from opkg.