Translation:The Dutch eat fruit in the morning.
In English, most commonly we use the word 'fruit' as both the singular and plural version of the word, as we would in the sentence 'Dutch eat fruit in the morning'. We do occasionally say fruits, but not very often - an example would be: There are various fruits to choose from. This one is a bit tricky!
Yeah, "fruits" is mostly only used to talk about kinds of fruit, especially in pretentious advertising.
tunda = fruit; a piece of fruit
matunda = fruit; pieces of fruit
aina za matunda = fruits; kinds of fruit
I hope you reported this as unnatural English and didn't just write about it here. The creators are not notified of these discussions.
The "fruit" issue seems to have been fixed (to the extent that "fruits" is no longer accepted). If in your dialect you can use just "Dutch" as a noun, that's not accepted (this would be a correct decision for my dialect, in which "the" is required, or you have to add "people").