I just have the TP-Link Archer C3150 working. I cannot access the internet using WiFi. I bought this, because the WiFi with my ISP router/modem wasn't stable. 

But it still isn't stable, it's faster now on the TP, but still not stable.

Itried to fix the channel and I have tried using WIFI analyser on my Samsung S7. It gave different results which channel I should use. Screenshots are available if you want to see it.

The amount of Wifi networks is limited to only my house. I live in a rural area. So my neighbours hardly show up. My house is not very big (128m2) and only 1 floor. The router is placed at a height around 2m and almost in the center of the house. The walls are made of 4 cm plaster panels which are attached to with a wooden construction. So no concrete walls.

Netflix is sometimes slow and the most issues we have is playing brawl stars (an moba game, played on ipad and my samsung S7). When we play we almost always have the issue simultaniously. The slow connection is not always the case.

I ran a speed test on my phone and we have a jitter of 30 ms. 

Download: 78Mb/s average.

Upload:67Mb/s average.

Compared to my pc (with LAN cable):

Download: 84Mb/s

Upload 115Mb/s

Jitter of 0.285 ms

The internet connection is glass fibre, with a "max" of 100mbit.

What else can I check do to improve wifi?