I see something else here and that are those spikes to 100ms or higher short bursts.
This sound to me something is not going well with one of the cables, have you tried using a different cable?
Different ports can behave differently with a possible bad cable.
I had a bad cable for 6 months and I was sure it was good until out of nowhere all connection dropped and even the pings where not revealing such heuristic like I have seen on your pic, your pic is better because it tells something bursts to high ms, for a local network that is quite unusual and can be a indicator of a bad cable.
^ i make my own cables, however this can also happen to normal cables, bottom line I used EZ rj45 connectors from a cheap brand with lose copper plates, and right when I tested a different router it happened, so bad cables can have different behaviour on different ports.
That is my public IP being pinged by a broadband quality monitor. Those 3 leaping bars are when I think the Flint is dropping the wan connection briefly.
I make my own cat 6 cables and have checked them with a cable tester. I have also tried a brand new out of the packet cat6, same issue.
Those thick yellow bars are not usually present on the Flint, only the cable router which is interesting.
I’ll show a graph from last week shortly. It’s a lot quieter.
I haven’t monitored carefully, but an anecdote: I’ve always been on stock firmware on the flint 3, and as of a recent update (kernel 5.4.213, OpenWrt 23.05-SNAPSHOT, f/w 4.9.0 updated 2026-05-15) I’m getting the random WAN packet loss too and it’s breaking connections to a bunch of sites. I think there’s a bugged update. I had no issues on the previous 4.8.x version afaik. My logs show netifd doing a renew and ping periodically, I think it’s timed with the dropouts? I’m running over wifi on a 6ghz connection. Might try giving it a factory reset.
I had this a few months back when I initially went from stock GL firmware to vanilla Openwrt 24.10.6. Random packet loss showing on my broadband quality monitor and disruption to streaming and teams calls. The connection was really unstable but in the logs, it wasn’t giving much info away. I ended up UBooting to 4.8.3 firmware and the issue went away…….after a good week of constant firmware flashing.
Upgrading to 25.10.2 seems to have caused the issue to re-occur again.
Unfortunately this time flashing back to GL firmware hasn’t resolved the issue.
I ran a continuous ping to my cable modem and there were no drops but there was also no packet loss.
I had a big burst of packet loss yesterday, it wiped out my official TV streaming box, it started buffering saying my connection was poor.
On my end, I just get random disconnects of stuff - mostly seen on websocket connections, where it’ll just eat itself. Checked with the ISP, it doesn’t seem to be their end according to their telemetry, so I can only assume it’s the router.