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try ethernet / wired connection... if the wired connection works then its your laptop wifi card or maybe a driver issue

It's gonna be hard when we also don't know your router/modem configuration, and so many other possible things, regardless i would get a usb wifi receiver if i were you, i got a very decent motherboard (Asus Maximus Hero X with onboard WIFI but the signal is often poor and also drops alot), with a receiver, no problems.

Are you using AT&T for your internet?

Found one possible solution (if you've already updated Windows and your drivers). Only takes a second and is easily reversible.

In Device Manager, find your ethernet card and right-click and go to Properties, then go to the advanced tab and choose Flow Control and set it to Disabled.

because we don't have all informations to give a advice that fits to all i would recommend

https://store.steampowered.com/app/403040/Driver_Booster_3_for_STEAM/
It's free and normaly your problems are gone after the updates.

It will take a few restarts. Calculate a bit time at the first run of it :o)

Does playing a game on a different client (epic / uplay) or with steam in offlinemode cause any problems?

At this point i'd suggest checking your router settings for closed ports or bandwidth caps.
Also the usual connection troubleshooting stuff: flushdns and cache commands in cmd, adding an exception for Steam on your firewall, changing DNS to Google's or Open DNS ones, etc.

Is the Wi-Fi wireless problem?
Identification is difficult.┐(´Θ`)┌

[Intel] Quick Checks to Improve or Fix Wi-Fi Connection Issues
If you do not check and improve such things?
May not work due to overload?
Heat dissipation may not have caught up.
Open the space around the laptop.
Improve ventilation.

It may be a simple reason.
Are you overloading your computer? Do you also have fever?
No?
It's like a microwave, TV or radio.
Find out if it is near your laptop, router or modem.
In some cases, changing the distance or changing the direction may improve.

Anyway, can only do this speculation because do not know the usage environment at all.XD