Hi Fraser,
I have my Netduma R2 router connected directly to Verizon Fios ONT through WAN. I previously had a ASUS router connected with no observable issues.
Some issues I am facing:
Slow initial loading on internet page
Download speeds reduce to KBs or come to complete pause/timeout
After router reboot no internet connection, have to factory reset the whole router
If it helps I am on Intel Ethernet Controller i225-V Lan Driver. My current PC used is NicksPC.
I should also note, I am getting my full speeds, 300/300 MBPS when doing speed tests.
QOS Screenshot
Device Manager Screenshot
Thank you