Not too popular- just very trendy (and so may date), but most people don’t care about that -or a lot of the names in the Top 50 wouldn’t be as popular as they are and timeless classics like William, Edward, Thomas, George, James, Michael, Charles, Alexander, Daniel, Joseph for example would be the Top 10 instead.
Chances are your Jude will still be the only one in class if that’s your worry, there will probably just be others in school - but that could be the case with many names, as it’s all area dependent and unfortunately ONS don’t have their old table anymore where you could check how many of any popular name were born in your area last year 😢 (the differences were huge!)
And while it’s not a name I like personally, I do think Jude is still a lot better than Chester. Chester is a nice city, but it’s not a very nice name - it works much better in America imo (where the usual nn is Chet), it sounds a bit downmarket/celeb wannabe here imo.