Apparently Rafael Rivera knows at least part of the cause, but doesn't seem to know of a solution.
You can see his response and his suggestion that could help us all at this thread.
Edit: I've noticed a number of other threads talking about the same issue. Seems it's more widespread than I thought.
So I'm having a very weird issue in the Release Preview that I never had on the Consumer Preview. This is running natively on my laptop (all specs here).
Basically, almost at...