Ereunate (search) is in plural (You, more than one person), active voice (subject of the verb is the one performing), second person (you, the persons spoken to).
Moreover it would be the present tense showing a continueus action, a habit, a practice onging at the time.
So John 5:39 would be: “You are searching.....” not a command to search or a recommendation to action.
I am not a Greek to English translation specialist...I don't even know Greek...
I could go thru the 26 or so Greek Lexicons out there and see how everyone disagrees with each other, but so many people have done that already that I don't think one more opinion would leave a mark...
Since all those Protestant KJV translators and those Catholic Douay-Rheims translators and those Aramaic translators disagree with the minor translations that are left and agree with each other, I'll leave it up to those experts to determine whether the verse is a command or a mere statement...But thanks anyway...