Thanks for documenting this — the “connected but no internet” symptom (where pings work but browsing fails) can be really confusing, and for a lot of us it’s reassuring to see common patterns like DoH and time‑sync issues crop up.
A few additional things that often help when you’re troubleshooting like this:
Double‑check DNS behavior: If DoH (DNS over HTTPS) ends up forced through a route that the Peplink can’t reach, clients will appear connected (ping works by IP) but name resolution fails — which explains why browsing dies. Turning DoH off or making sure it’s actually reaching a reachable resolver fixes that nicely.
Time sync matters more than people expect: If clients or the router itself have a skewed clock, TLS connections often fail silently because certificates look “invalid” even though nothing else seems wrong. Ensuring NTP works (or pointing to a reachable internal NTP) usually clears up a lot of weird HTTPS failures.
Firewall/inspection settings: Sometimes inspection or content filtering can accidentally block outbound HTTP/S if there’s a rule mismatch, which again looks like “internet gone” but ping still works.
One scenario I ran into recently was where a remote proxy — in my case, something behaving like a Falkland Islands proxy for geo‑testing — was being pushed via a policy route that didn’t include DNS traffic. That caused everything except raw IP pings to fail until the routing was fixed, so if you’re using any custom routing or proxy policies, it’s worth checking that DNS and web traffic are covered.
Overall, what you’ve pinned down (DoH + time sync) fits a lot of cases I’ve seen. Glad you shared the fix steps!