The dictionary entry is trying to explain a mistake often made by non-natives.
Those mistakes are these:
- suggest someone something [BUZZER}
- suggest someone to do something [BUZZER}
Suggest works like this:
- I suggest you finish early. [followed by a clause, with or without that].
- What did you suggest? I suggested cake, not biscuits be served at the party. [followed by a passive clause, same thing re that]
- I suggested he read the book to learn the rules of the game.
Recommend works like this:
- I recommended you leave early. [clause]
- I recommended him (for the job). [indirect object,him]
- I recommended the job to him. [direct object, job]
- I suggested that, not this. [direct object]
No, you cannot "recommend someone something", just as the Collins says. But:
*You can recommend something to someone
*You can suggest something to someone.
As for the difference, a recommendation is more formal than a suggestion.
- I suggest you close that window. It's cold in here.
Closing a window would not usually be something you recommend in casual conversation.
However, you might say to a friend: I recommend you see a doctor for that knee.
- Experts have recommended we keep the windows open as late as possible in the season due to the Covid-19 pandemic.
recommendations are generally more formal things compared to suggestions.
[reference: me own head]