Searching engine over SharePoint List doesn't find existing item

Hi, 

For a long time we have problem with searching withing SP list. List have up to 300 items. It search only some of them. But (for example) when we're searching item which ist in first 10 in list, so engine doesn't look for it. Example on the picture 

When we look for Abvest or Abv or Abvest s.r.o., srch. engine give me (the message: No items match your search):

I'm searching based on Title column, but it doesn't work on the other columns either. 

It's disappointing because I don't know how to fix it or reset the search engine. 

Does anyone have experience with this problem, or at least partial advice?

Thanks!