Can a human body interfere with 4G or 5G?

I have two questions;

A colleague and I argue about whether the Wi-Fi signal can disappear or be disturbed if you get too close to the laptop. ^^

Personally, I'm in favor of no since 4G and 5G. (Telekom)

But can't make it clear to him ^^

If the body can't influence that, could you please describe exactly how and why if that works?

I go there with you no

Since every user is sitting close to his Läppi, I only 20 cm from my Wi-Fi stick, you don't have to provide any further reasons.