The word has no fixable meaning.
A broken chair leg might be fixable with some wood glue and a few nails.
It is common that these pianos can rapidly become very expensive to repair and/or maintain if at all fixable.
If it's appropriate, talk to your boss about your concerns and try to view the sleep problems as temporary and fixable.
Don't give up on your sleep apnea treatment just because of an easily fixable problem.