I just retested again. Connected the Mango WAN port to the LAN port on the WAN router then connected my laptop to the Mango WIFI upstairs. The WIFI kept dropping so I couldn’t even complete the test. I am now sat a few metres from the Mango and I get these results:

DOWNLOAD Mbps
1.21
UPLOAD Mbps
0.14
Ping ms 229 191 185