Why is the speed of WiFi 2.4 GHz twice higher than 5 GHz?

Laptop Acer Nitro 5 an515-54-58tj, accepts built-in Intel Wi-Fi 6 ax200 1600 Mhz, router Smart Box GIGA, the rate is 100 Mbps. The router gives out both 2.4 GHz and 5 GHz band.

INTERNET SPEED on 5 GHz band

Incoming connection: 37.46 Mbps=4.68 MBytes/sec.
Outgoing connection: 92.52 Mbps=11.57 MBytes/sec.

INTERNET RATE on the 2.4 GHz band

Incoming connection: 87.76 Mbps=10.97 MBytes/sec.
Outgoing connection: 91.59 Mbps=11.45 MBytes/sec.

All tests were conducted one meter away from the router. Tested on Yandex.Internetometer and Speedtest.
At the same time on the 5 GHz range only 2 signals from neighbors, and my channel is completely clean. Range 2.4 GHz in addition to me about 15-20 signals.

Answer

I would suggest to start by measuring the speed on another device. Preferably on a phone or tablet. In the range of 2.4 GHz and 5 GHz. I think a lot of things would become clearer. Ideally, of course, connect the laptop to another Wi-Fi network in the 5 GHz range and take measurements too. But I realize that’s probably not possible.

You have good speed in the 2.4 GHz band, almost maximal. In the 5 GHz band, it is unlikely that the speed should be much higher (since it is 100 Mbps from the ISP), but in any case, it should not be lower than in the 2.4 GHz band.

The reason could be the operating mode and channel width at which the Intel Wi-Fi 6 AX200 adapter connects to your router. I don’t want you to immediately change the wireless settings on your router, so let’s first look at the properties of the Wi-Fi network in the 5 GHz band on your laptop. We’re interested in what protocol is listed there, 802.11n, or 802.11ac.

Wi-Fi speed 2.4 GHz over 5 GHz