Rogers Technicolor CGM4140COM in bridge mode
Ubiquiti EdgeRouter Lite (ERL-3) router behind it
Kanata (Ottawa), ON
1 gigabit/30 megabit package + Ignite TV channels
946 down/31 up, no issues
Once every 1 to 1.5 weeks the speed doesn't exceed (any speedtest, consistently) 650-680 megabit down.
Complete power off to both cable modem and router for 5 min - no impact, still (!) 650-680 megabit down when all powered up and running.
Router restart - no impact.
Cable modem restart - no impact.
Troubleshooting (the weird part):
Change the cable modem from bridge to gateway mode (90 sec).
Restart the cable modem (3-4 min).
Change the cable modem back from gateway to bridge mode (90 sec).
Speed test - back to 946/31:-).
The best uneducated explanation I can think of is the cable modem "syncs up" with Rogers' servers at a lower speed for some reason, the power off/on doesn't change that synced up speed, but this bridge-->gateway-->restart-->bridge sequence somehow forces to re-negotiate the speed back to the maximum 946 down.
No idea what to do about it, and even if anything can be done about it...
Found it! @KoN1 reported the same problem here: https://communityforums.rogers.com/t5/Ignite-TV/Using-the-Ignite-TV-Modem-Gateway-in-Bridge-Mode/m-p...
You also both happen to be using Ubiquiti routers that run EdgeOS. When your Internet suddenly slows down, what happens if you were to unplug your router, then connect a computer to the XB6 while it is still in bridge mode and perform a speed test? Do you see the same results?