Although you can turn the S-Pen detection off in the settings to prevent the battery drain, it is by no means a 'normal issue'. I'd say you need to get either the S-Pen replaced or the whole tablet (and I'm pretty sure you're still covered by warranty, provided you haven't rooted yet).
If possible, get another S-Pen and try that one in your tablet. Does it exhibit the same behavior? If it does, it's the tablet, you need a replacement. If it doesn't, try the next suggestion.
If you were able to get another S-Pen, I'm assuming there's another Note 10.1 2014 to go along with it. Try YOUR S-Pen in that tablet. Does it act up like yours? If it does, then it's the S-Pen that needs replacing.