Mandolas 03

I bought an octave mandola last year and have been playing away on it. The last while, however, the intonation on it hasn't been the best: Whenever E played on the seventh fret of the A string is in tune with the open e-string, the A at fifth fret on the e string is sharper than open A an octave lower. I realise that this may be a product of one or a combination of several things including old strings or a warped neck (unikely as this is a new mandola).

Tutorial on Mandolin Acoustics from The Lefty Luthier | Custom Mandolins, Mandolas, and Mandocellos