I manually updated to 10.5.20.3 on my 770

VINE0001​ first, IPv6 is VERY flaky right now. If you don't need it, disable it. NG has acknowledged this and is working on it.

Second - if you want to test it some just for fun, I know that Edge (Chromium) is more “aggressive” about using IPv6 (and HTTP/3/QUIC + DoH) than Safari. So Edge keeps trying the broken IPv6 route and doesn’t fall back cleanly, while Safari usually drops to IPv4 quickly and the sites load.

Here's how it happens, possibly:

 • Different DNS paths: Edge may be using Secure DNS (DoH) directly to a provider over IPv6. If that IPv6 path is broken, name lookups fail for Edge, while Safari uses the macOS/system resolver over plain DNS (often IPv4) and succeeds.

 • Fallback behavior: Safari tends to fall back to IPv4 faster. Chromium will often “stick” to a v6 AAAA it resolved and not pivot as quickly if the v6 connect stalls.

- there is also the potential that Edge jumps to QUIC faster than Safari, with the same result of getting hung as it locks there. - QUIC is an optimized network transport layer protocol that browsers jump to, again Edge might be getting hung there.

A few things you could play around with on one computer: (I am on Edge beta, these should be right based your version)

 1. Edge → use system DNS (or turn off DoH)
edge://settings/privacy → “Use secure DNS” Off, or set Use current service provider (not a fixed provider).
Then:
 • edge://net-internals/#dns → Clear host cache
 • edge://net-internals/#sockets → Flush socket pools
 2. Disable QUIC (temporarily)
edge://flags/#enable-quic → Disabled → relaunch Edge → try apple.com, wsj.com, microsoft.com.
 3. Per-site data wipe (for the failing sites)
edge://settings/siteData → search apple.com / wsj.com / microsoft.com → Remove.

Do these one at a time and test.