Yes, if you turn off wifi and turn it on again it will be ok. Until it doesn't work again.
In my case, turning BT off solved the problem. Whenever I turn BT on, wifi speed drops dramatically and after a while it stops. This is also the case for mobile data. When BT is off, there is no problem.
---------- Post added at 12:42 PM ---------- Previous post was at 12:41 PM ----------
Yeah I know, I tried that. But no luck.