RBE771 slow download

I'm having the same issue but everything I've tried is over a wired connection - no wireless.

This is what I've experienced.

I've just started using Ziply Fiber and signed up for the 2000Mbps (2 gig) plan.  I've been running an RBR750 (supports 1 gig) that has been working fine.  Speedtest speeds on the RBR750 over wired connections have consistently been ~900Mbps down and ~850Mbps up (have tested this for about a month since upgrading to the 2Gbps plan).  This is expected as the RBR750 only supports 1 gig.  All of my testing has been over a wired connection to two separate and powerful Windows systems - 1 running Windows 10 and the other Windows 11.  Both systems have consistently reported the same download and upload speeds.

Since the RBR750 does not support 2 gig I purchased the RBE771 that does support 2 gig.  Before any testing began I upgraded the firmware to the latest.  After configuring it in exactly the same network configuration (everything wired, etc.) I used the built in (on the Orbi router) Speedtest app and I got about ~2300Mbps down and ~2200Mbps up.  

When using the Windows based Speedtest on exactly the same Windows systems, configured with the RBE771 (2 gig) router I consistently get ~450Mbps down and ~850Mbps up.  Thinking that something might have changed that caused this issue, I switched back to the old RBR750 (only supports 1 Gbps).  I once again got ~900Mbps down and ~850Mbps up speeds using the Windows based Speedtest on the two Windows systems.  Just to clarify, the only thing that has changed (between these two tests) in this environment is the Netgear router.  Nothing else has been modified.

Clearly the RBE771 router is suspect.

I called NetGear support.  No love.  They suggested all of the usual stuff (reboot every component, etc.).  They eventually said they had to get off the call but would call me back.  Have not heard from them since.

Any thoughts?