my point was not the radiation pattern of your own antenna per se, the access point has a radiation pattern as well. It takes two to tango in this case as the communication is bi-directional, even if you are just downloading.
What kind of connection is there between the antenna and the rest of the system? Myself I’m using a device called “Badboy” and that has the whole WiFi system build into the base of the antenna. There is only Ethernet cable coming from it connected to a POE adapter and subsequently to a Draytek 4G router. This chooses which connection to use (4G/Badboy) depending on available bandwidth.
The Badboy is isolated from everything apart from the POE injector and the Router.