The Internet works if the notebook is near the Internet router. When he is in another room, then the internet will not work.
Old notebook HP with atheros chipset, works even when it is far from the internet router.
I expected that a notebook with a Realtek chipset could work like that, but ...

I need a wifi connection.

Device-2: Realtek RTL8821CE 802.11ac PCIe Wireless Network Adapter
driver: rtw_8821ce

Laptop System: HP product: HP Laptop 15-da0xxx.
I installed Salix 15.
Wifi it works badly. Reconnects constantly, internet connection is lost.
I installed the Realtek driver from Slackbuilds.org. It still works ...

When I install Salix 15, it takes up 9.5 GB.

Do you know what linux driver is required for your nvidia card? Driver 470.xxx, or driver 525.xxx or some other?
Run live linux Mint or live Ubuntu and see what driver it offers to install.

I found a solution for the old graphic. Do not install codecs, add MPV player. Video from the Viber application works through the MPV player. Solved.

Viber doesn't work with the Nvidia card GT 8400S. The card's old.
With the Nvidia 710 GT card with the proprietary driver 470.xxx and nv codec with SBo, Viber works correctly.
It's up to the old hardware, after all. It's not Viber.

Thanks @gapan, i will wait for the newer version of viber with SBo. Maybe it will be better.

Viber crashes after installing multimedia codecs. When codecs are not installed, viber works, but some video formats cannot be played.

Instead of an open source driver, I installed an nvidia-legacy340-driver, the viber doesn't break.