You sure nobody in your house was playing around with the player, and un-linked and re-linked the account, or changed the account? Or did someone maybe reset to factory defaults, and never finish the process?
...There was maintenance worker in my apartment the day this happened while I was at work, so technically someone else did have access. I highly doubt though that would be the cause, none of the remotes were moved, and I doubt he would go through the trouble of messing with my Roku. Maybe there was a power surge due to the work he was doing, and this caused the behavior? Maybe a software/hardware glitch caused the Roku to think it was unlinked?