I got some feedback from David Heath. He said, that the problem on my case might be nutrients. My brews were low og. beers so the lack of nutrients made yeast to stall.
I have a same problem. One week on fermenter at 30C (86F). Bottles I kept 3 weeks at same temperature. After one month on cellar The nasty yeast bite have'nt gone. The beer IS undrinkable. This happend to me twice! All My other brews with different yeasts are really good so it's not in my...