Windows Update causing high CPU usage from Windows Defender

Recently whenever I open up Update & Security in Settings, it causes Antimalware Service Executable (aka Windows Defender) to flare up in CPU usage by 10-15% and slow down everything else on my computer for the next 10 or so seconds. If I back out into the Settings menu and click on Update & Security again, I won't get the CPU spike + slowdown but if I close out of Settings and click on Update & Security it'll happen again.

This has been happening for the past few days; while I haven't explicitly paid attention to this before in the past, I'm fairly certain that I would have noticed if it had happened before.

Nothing else has slowed down my computer like this, not even games running at max settings. In fact, games actually use up more than 10-15% CPU but don't slow down my computer at the same time.

I've ran sfc/ scannow and malware scans which both came back clear. I don't get the slowdown when "Real-time protection" is off, but that's moot considering Defender isn't even on anymore at that point.

Is this happening to anyone else? Is this the result of some botched definition update? Is there a way to exclude update components from Defender? It may be inconsequential, but I'd still like to get some feedback.

Noted your similar post here:
High CPU usage from Windows Defender - Windows 10 Forums

You can delete a post.. bear in mind that threads get a reply if anyone who happens to read it has anything useful to share- remember everything is voluntary. It's not a paid for service...

High CPU (RAM, Disk etc) usage is relative to that parts performance so that should be included in a question. Some dual core would always be under higher load than some 8 core processor, RAM, quite different if you have 2Gb or 32GB. 5400rpm HDD and M.2 SSD.