PS4 reboots and possibly loses data?

So this is the second time this has happened to me, and I'm wondering if other people have had this issue or have any suggestions.

Basically, both times this has happened, I was watching YouTube with my phone plugged in to one port to charge, and my extended storage in the other USB slot, the PS4 rebooted automatically, told me my extended storage was not disconnected correctly, and it would need to be repaired.

I did that, and as soon as it rebooted, three games suddenly had to download data. I believe this is due to data loss after the restart, as there were no pending patches before restarting.

So I'm basically looking for suggestions as my Google searches are coming up with nothing.