I’ve got two Flint 2s (one as an AP and the other one as the main router). They are on channels 64 and 128, respectively. Both are at 80 Mhz as that is the maximum supported by most of my devices. When they first boot up and after they complete the DFS scan, the WiFi speeds are amazing (around 800 Mbps, which is almost as fast as my 900 Mbps connection. However, a few days later, they become a bit slower and settle at 550 Mbps. Rebooting both brings the speeds back to 800 Mbps.
I understand that, for WiFi, 550 Mbps is still extremely fast. However, I do like to tinker with things and optimise them as much as possible so I would like to figure out why the system slows down. I’ve scheduled two weekly reboots overnight at times when I don’t expect to use the WiFi. However, I would like a more permanent solution. Does anyone have any ideas? Thank you in advance.
Especially if you do alot of consuming tasks or have an bussy network, multiple switches involved?
Here is something I found out and asking help on OpenWrt forums, and this also happen on the most recent OpenWrt.
And that is hardware offloading/hardware acceleration.
If I mix multiple versions of stp like rstp on my network switches I made a broken network, you want to use stp on all, so I did.
Now it comes:
even with the proper fix is in place, if I download on lan1 on a vlan which isn't involved on lan2 at all, lan2 starts randomly shouting that it is sending its own source address as of the router and locksup, it also spams bdpu changes.
So what has this to do with your issue:
Frankly I came to the conclusion hardware offloading can do really unexpected and broken behaviour if the conditions of alot connections or firewall rules are met, can you try for me to turn this off and see if your speed still randomly changes?
If it happens packets get discarded by the cpu, and things break maybe also checksum wise.
A other possibility may be a few things here:
adguard is using too much lists
the router is used as a media device for streaming (yea this is not a good idea)
I have observed a weird bug on my phone and it only happened to me once, when I switched alot of times from wifi networks, out of nowhere it degraded, until I had 10mbps download only a reboot fixed it and it was not the router (poco x6 pro)
there could be a problem with problematic devices spamming dhcp requests rather than acknowledging them, if that happen also take a look if you see AP-POLL in your logs you may want to change something then.