Solution for slow wifi after Oreo update

I just uploaded my Samsung Android to Oreo (8.0) and as soon as the update finished I had issue with wifi. The connection was very slow or sometimes no internet at all.

I looked a lot of forums and did a lot suggestion such as deleting the cache, reset network setting, forgot password for the wifi connection and etc.

Finally the thing that helped me to solve my issue was this:

Enter *#9900# and press the green key (in my case it worked without pressing the key) will open a menu.

First I chose DELETE DUMPSTATE/LOGCAT

then I changed WLAN FIRMWARE DUMP MODE to ON

Also there is another option named: WLAN ADVANCE DEBUG, which can be used for debugging.

I did a lot of search and nowhere could find a useful solution, I hope this help someone with the same problem.