RBRE960 limits MacBook Pro download speeds to 80mbps max

I have an RBRE960 with two satellites all running the latest V7.2.8.5 firmware connected to my provider's router via a Cat 6 ethernet cable.

I have a 1 Gbps connection; the 960 consistently shows >= 900 Mbps on a speed test.

I have two MBPs – one a personal one, one work – that 5 GHz connect to the Orbi at a Tx rate of 1,300 Mbps, but have a max download speed of 80 Mbps.

Both MBPs are updated with the lastest macOS. Each MBP is connected to a different satellite.

If I connect the MBPs to the provider's router (which is in my basement), I can connect at >=500 Mbps, so it's not the MBPs; it's definitively the Orbi system causing the reduced download speed issue.

I've tried everything short of resetting the Orbi system to factory settings (resetting the MBPs, limit tracking on/off, spoofed MAC address (to see if it's tied to that)), etc, but I can't find a solution. I'll reset the Orbi system if I need to, but wondering if anyone has run into this situation, and if so, what the fix is.

Thanks.