"Bonvolu" is already used with -u so it has to be followed by an infinitive. The phrase can be roughly translated as "Be so kind as to check"
It could also be "Bonvole kontrolu" (kindly check).
But either way, only one of the two verbs can be in the imperative.
There is also another problem: "Please, control" is considered a wrong answer. Can somebody explain me why? Well, the two terms are not identical, I agree, but both are translated by "kontroli". Aŭ ne?
I would say no - "to control" (as in to have under one's control or to exert control over) is "regi" or "gvidi", while "kontroli" is "check" (to see whether something is the way it should be, or to see what something is like).
Actually, that's one of the definition of control in English, albeit a weak one. Control originally meant to check and verify, and is used in that way in management terms such as quality control.
In many contexts, "control" is not synonymous with "check"; and it goes the other way frequently. Often, checking that a thing has been done indicates control, as you'd be expected to remediate a deviation in many contexts; whereas controlling usually indicates expectation of deviation and required action. Quality control is a good example: we know quality will deviate eventually, and so quality control is continuous verification until a deviation requires remediation.
In terse messaging, "Please control" is a valid statement. It's unlikely as a common idiom. "Please verify" is fairly likely.
But if you're learning how to translate then obviously you'd never use it like that, technically correct or not.