I have been reporting this bug for over 7-months now, but it is still happening on a regular basis. THIS NEEDS TO BE FIXED!
Approximately once every 7-8 days on a consistent basis, the Hull HP Capacity of my ship will suddenly drop 10% for no reason at all. It will stay that way for about 2-3 days, then return to its normal number. I have been struggling with this problem for months now and still haven't found an explanation why it's happening. The only thing I can think of is perhaps the starship mastery; which adds 10% HP, is bugged. Or maybe the Bulkhead Technician Trait. Perhaps they don't work on certain times?