@KimcheeGUN I have the defaults for anything like that. Where would I find that in the router admin interface?

@djsdjs Ok, this morning I ran StarTrinity to compare and it shows the ER605 to be much better. Ookla and fast.com also show speeds around 500/500. The switch over was done at the time marker...

@Clive_A Everything else was identical on purpose. I did try OpenDNS (like the old router) and the default ISP DNS.

@djsdjs Ok, after I re-installed the R600VPN one, it initially had the same speed reduction as the ER605. Now that it's sat overnight it's back up to over 200 Mbps. Is there anything about the router...

@djsdjs OK I've tried all these firmware versions - all the same results. So odd that the old router is over 5 years old and works better. Gonna reinstall the old one and send this one back....

The first screenshot is the speed of my old TL-r600VPN about 30 minutes before swap out with ER605 which is the second screenshot. The download speed has dropped to less that 1/4 of the older router...