> It is connected to the hub by a Cat6 cable.
When you say this, do you mean you have another MX as your main security appliance, and then you have this MX64W being used only as an access point?
Are there any other access points in the environment?
Are you saying users are 69m (75 yards) from the MX64W?
When users connect to the WiFi, is is clear and unobstructed, or do they have to go through several walls?