Thanks for demo @gabor.nagy I was trying to reproduce it with a simpler example and I tried array of arrays, array of objects and everything worked fine till I came up with an idea that’s maybe the amount of data is a problem.
I’ve updated your demo http://jsfiddle.net/1zkt9yzg/1/ by changing ‘html’ values to an empty string and it solved the case. There’s an issue with displaying a lot of HTML content. Here’s a simpler example that I’ve made http://jsfiddle.net/msk8zzue/1/ where the height of rowHeaders is also incorrect.
I will try to dig deeper to find a solution.