I've had this problem on 2 different machines both running Windows 10 (and previously 8.1). I was able to 'fix' it, but the solution was ugly and Windows updates sometimes undo it.

This is based on advice I eventually found in another thread. For that individual the specific process was different, but essentially to diagnose the problem open up device manager and show hidden items. You have to tediously wait for the problem to occur and then check to see if the device manager refreshed at the same time. If it did, then a process is starting/ stopping/ rebooting and interrupting the controller (this probably shouldn't actually cause a problem, but somehow with XIV it does).

For me it was always the Volume Shadow Copy service (VSS), which is a key component of the system restore feature in Windows. I personally never use this and don't anticipate ever using this, especially with nearly everything important being backed up to remote servers. Disabling this process (and preventing it from running on startup) solved the problem for me.

If you don't use system restore and want to skip the diagnostic phase and jump straight to the potential fix, you can just open task manager, click on the 'Services' tab, click 'Open Services' on the bottom of the window, find 'Volume Shadow Copy' (sorting by name helps), right click and select properties, and change startup type to 'Disabled'.

This should stop the process and prevent it from ever starting back up without specifically changing it yourself (though as I said a Windows update reset it on me at least once). Hope this works for you!