With WPA2 encryption: 49/110, 45/105, 18/75
Without Wlan encryption: 264/514, 255/508
Tested on a OnePlus 3T.
One a 2012 ThinkPad W530 using Speedtest.net instead of Speedflex is about 50/50 with a password. 100/110 without a password.
Looks like it's an encryption issue. I wonder if removing special characters from the password would do anything?
Can't believe this hasn't been addressed, as few companies are going to want an open WiFi network.