World of Warcraft is a CPU heavy game, that's likely using up all of 1 CPU thread. It is not well optimised to use multiple threads.
This is legacy wow, not retail. You can, and I did run this on an old single core 1.7 GHz and back in the day. This issue has been only going on for a couple of weeks and I've already reverted windows back to a save point before this issue.
you mean to tell me that this exact combination of processes that ive been doing for the last 624 weeks~ this this build and other, lesser builds, have all been an anomaly and this perceived issue in the last two weeks have been "working as intended" .........
the issue isnt just that one core is being used 100%, thats fine, its that its trying to run all of the processes on that same core and it literally wont play a youtube video while im playing a videogame... it just will not function currently doing both.