wireshark not capture http POST request

hello

When I run wireshark on some public wireless (without password) , I can see GET requests from many users that surfing the web, and no POST requests. when I filter "http && tcp" I can see all the websites that the users visiting and can read the html code of their visitis. (there are a lot users in this wifi) .when I filter http.request.method == "POST", I get 1 - 4 lame packets that belong to some XML and not even use web. it doesnt make sense. like I said, a lot of users use this network. and there are a lot of packets when I filter http && tcp , so the users are use the network and surfing.

When I run wireshark on another wifi (with password - also , lot of users are conntented to this wifi) , and I filter http && tcp, I can see only my computer's traffic. but when wireshark shows all the packets, I can see that there are a lot of another devices uses the network with another protocols.

I use kali linux. I turned on monitor mode and start airmon-ng on the wireless interface.