After I tested affix on my website on iPad I find out that it is not working properly and I goggled that it is problem with iOS https://github.com/twbs/bootstrap/issues/11560 and currently there is no easy solution for that.
iOS just has problems with calculating fixed position as you scroll. Basically you don't get an updated fixed position until a slight delay after you stop scrolling
Is there anything I can do to make it work, may be some one already done some work around?
This, sometimes, made the trick for me.
It enables hardware acceleration on iOs devices, and the scroll position is calculated faster.