@
jbuehler
: concerning constant tuning needs and then even freezing, that doesn't sound good at all.
The Prologue tuning desaster lasted nearly a year, concerned ALL Prologues I ever played, and was met with utterly disgusting, ignorant and impertinent silence from the Korg Japan management over the whole period, while they continued to sell faulty devices no matter what. No serious company behaving responsible does that: an utter NO GO experience.
Since the issue was finally fixed with an update, my Proplogue 16 has been quite stable concerning tuning: I only have to retune casually after warming up, and certainly not as frequent as described by you. It's essential to follow all OS updates with following re-calibartion as described in the manuals, to exclude missing calibration after OS updates as possible source of trouble.
Now the first thing you probably should try to find out is a) if only your device (or a bad batch) is concerned, which I hope for everbody, or b) it is a widespread or even common XD problem.
In the first case, just exchange your device against a working new one as soon as possible within guarantee. In the scond case, get rid of any XD and return your device completely, until it is clear that the problem is reliably fixed. I wish no one the lousiest Korg time and crappiest Korg Japan support I ever had in all my life, with my Prologue buying and using efforts over many months, without ever being able to use a fully paid synth all that time, neither live nor for recording.