Internet speed is slow

[megavolt]

This just disables other protocols than 11b and 11g. Meaning these ones: IEEE 802.11 - Wikipedia

@Goldy1940

options iwlwifi 11n_disable=1 # disables 11n connections
options iwlwifi disable_11ac=1 # disables 11ac connections
options iwlwifi disable_11ax=1 # disables 11ax connections

By default it uses the hardware on the chip for encrypting the connection. This replace it with a software one, what could result in a faster connection:

@Goldy1940

options iwlwifi swcrypto=1 # enables software crypto

That disables the power managment of the wifi card. That means it will always stay at 100% and don’t try to save power:

@Goldy1940

options iwlwifi power_save=0 # disables power management

@Goldy1940

And is there anything else I can do by your help so that speed reaches around 40.

So at this moment both connection are equal balanced (Download and Upload)…

Replace this option (1->8):

options iwlwifi 11n_disable=8

Explanation:
RX → Download
TX → Upload

11n_disable: disable 11n functionality
bitmap: 
1: full
2: disable agg TX (uint)
4: disable agg RX (uint)
8: enable agg TX (uint)

I am not 100% what the result will be, but worth a try. So as @Olli suggested.