Products search bug [OpenCart 2.1.0.1]

Hi,

I'm using OpenCart 2.1.0.1 default theme, when I search for products it ignores the fourth letter in each word for example: I have only one product named [b]GloryKylin HDMI EZCast[/b] when I search for [b]cast[/b] I expect to get all products contains the word [b]cast[/b] instead I get list of other products like iPhone [b]cas[/b]e, Samsung [b]cas[/b]e and ...ETC. so in my case when I search for [b]cast[/b] it ignores the fourth letter in [b]cast[/b] word which is [b]t[/b], but if I search for [b]casts[/b] it displays the product [b]GloryKylin HDMI EZCast[/b] and there are no products contains the word [b]casts[/b] but it displays the product anyway because it ignores the fourth letter in casts.

thank you