Slow wifi speeds

Hello,

I live in the UK and have one gigabyte broadband with Virgin Media.My RBR850 - Orbi Tri-band Mesh WiFi 6 Router(RBR850) is plugged into the Virgin Hub 4. I have one Orbi satellite upstairs. My laptop is a MacBook Pro with these specs: 802.11 a/b/g/n/ac.

This is what happens when I test the speeds with no other devices on the network:

When connected to the Hub 4 or the Orbi base station by an ethernet cable, I regulary get over 900Mbs of broadband. But when I hop on wifi, sitting two feet from the base station, the rate falls to between 200Mbs and 450Mbs.

I get the same numbers when I run the same two tests (Ethernet vs wifi) using the Orbi satellite upstairs.

But whenever I check the Orbi app it says that my MacBook is connected at a Link Rate of 975Mbps. (I'm using my iPhone 7 to check. At the time of checking there are then obviously two devices connected to the Orbi mesh network. The app says the iPhone is connecting at 875Mbs.)

What's going on here? Shouldn't I be getting more or less the same bit rate via Ethernet and wifi? Especially standing so close the Orbis?

Thanks for your help!

Carl