How to set up a wifi router?

Question

Computer networks

I recently connected the "Planet" provider, there is no way to choose another.
The router was issued SNR-CPE-W4N, already configured.
100 Mbps are connected to the router via cable, test (Yandex Internet)
The router distributes only 40 Mbps. (again, Yandex Internet)
The router is 3m away from me, while the quality of the signals is disgusting, the ping in games jumps from 50 to 300.
After a few hours, the Internet starts to disappear altogether, restarting the point helps.
Tried changing channels, didn't help.
At the same time, there are not many wi-fi points in my house (only 5).

The router itself:
Router Settings:
Basic
Advanced
Security

Maybe my settings are not correct, what should I do in this case? It’s not realistic to live with such an Internet, you can’t watch online videos, you can’t play online games.
Solution:
The problem was solved, as TNAT said, the router processor was loaded with no options needed.
Disconnected this, the Internet began to fly, the ping became stable, the Internet disconnects disappeared.

Thank you all very much for your replies

Answer 1

The situation with the congestion of the air is normal. It happens even worse (I now have more than 30 points with a signal above 30% and it's okay).
Some routers react completely inadequately to the settings.
In addition, it may not be the router that is to blame, but the device receiving WIFI.
Try to look for a combination of suitable settings.
1. Channel width 40 megahertz
2. Reduce power by 50% if the router is only 3 meters
away 3. Manually change the channel, sort through, find where it is better. Usually 1-2-3 channels are better coordinated with the antenna, but the workload on them is also greater.
4. Try to disable any enhancements, filters (such as TX Burst for example) - unload the router's processor. Ping jumps can be associated with increased load on the router, the firmware does not cope with bugs
5. If the troubles begin after a few hours, the router may be overheating due to an unsuccessful design or location.
I came across such "free" routers where the inclusion of some kind of harmless function led to a drop in speed.
Recently, for example - in a cafe, home Internet is connected with an ADSL "free" router, it hangs when a lot of people (connections) are crowded in the cafe. The router cannot be replaced. You can't wire them all.
I had to transfer the router (with some hack) to the transparent bridge mode and connect my own, tested router.

Answer 2

Connect by wire. Trying to squeeze high speeds and good ping out of wi-fi without knowledge, just following random advice, is a thankless task.