I went ahead and updated the title here about the fuzzy graphics and FPS drops to help get traction to this thread!
Could you include the details under Apple Icon > About this Mac > Overview tab?
This information will help us see if there’s any common hardware or OS we should look into! Thank you for your reports, everyone!
Yeah I should have said - I am running on 10.14.6 Mojave, not Catalina. So I don’t understand the issue all of a sudden with the graphics on a video card of this power. It was working fine yesterday.
Sure, it’s an iMac 5K, 27-inch 2019
3.7ghz Intel Core i5
40gb DDR4 RAM 2667mhz
AMD Radeon Pro 580X 8gb
1TB SSD, with 637gb free
Edit #2, I also did a reset to “Recommended Settings” and that made it even worse.
So sum up, under 8.2.5, I had 60+ fps with it set on 10, nearly 120fps if set on a 5.
Logged into 8.3 today, and saw it was reset to a 5, and got 30 fps, did a rest and that didn’t help, changed it back to a 10 and get 22fps. Not happy. 
Having the same issue, but my laptop starts to freeze and then completely restart. Hope they fix this soon for mac users
Okay, I just saw this same behavior and wanna post this FYI:
It looks like the Display Mode settings have reset to whatever resolution your Retina display is set to appear as. So, for example if you have a 5K display but have your screen size set to look like 2560x1440 (or 200% scaling), then WoW will now default to that in the fullscreen size settings and then upscale it so it’s all fuzzy.
The fix is to just go into your graphics settings (in WoW) and set the Display Mode screen size to whatever your actual resolution is, so for 5K it would be 5120x2880, for 4K it would be 3840x2160. Then, make sure that your Resolution Scale setting it set to 100% (which should match your resolution).
This should clear-up your fuzziness right away!
Disclaimer: Note that this is only a good idea for folks who were already running at 100% of their native resolution before the patch. If you try running 4K or 5K native resolution at 100% scale on an integrated GPU, it won’t be pretty.
Hope this helps!
iMac Retina 5k, 27 inch, 2017
10.13.6 High Sierra
4.2 GHz Intel Core i7
Radeon Pro 580 8192 MB
16 GB 2400 MHz DDR4
Thanks for your reports everyone! After discussing this with our team, there’s been some UI scaling changes which are intended and can cause the blurriness in-game. The game now renders the UI as the same resolution as the game and will no longer use render scale. This results in some fuzzier graphics for some users.
Allyriae hit this on the nail. This should help with the fuzzy graphics! Please check out their post here 
To explain this a bit further, some systems will be looking to set the resolution closest to 720p, 1080p, and 1440p, instead of using the render scale.
For example, on a 4K laptop, it’d be 3840x2160 at 50% render scale, now it should be 1920x1080p at 100% render scale. Adjusting these settings for the resolution drop and and render scale slider, should get it similar to how it was before the 8.3 patch. Hopefully, this helps with some of the FPS drops as well!
MacBook Pro (Retina, 15-inch, Mid 2014), Mojave 10.14.6
Resolution 1440x900
ALL settings on low, 30 max fps, 8 low fps
Character selection screen
120% CPU
Looks like 8.2.5 “infinite loop” bug once again
Confirming this seems to have fixed my issue - 5k retina display iMac
SO i also use an iMac, but a 2014 one. I noticed the blurryness as well but saw that my resolution got turned down for some reason when i downloaded the patch. Im still having FPS issues though, I can’t fix it… and its making the game un-enjoyable. Before 8.3 i would run around boralus at 50-60 fps and higher in the open world. Now its down to about 20 in Boralus and 40 or 50 in the open world.
Same issues with additional crashing of game and laptop at stage 6 with magni in the forge.
MacBook Pro 13 inch 2015
2.9 GHz Intel Core i5
8 GB 1867 MHz DDR3
Intel Iris Graphics 6100 1536 MB
Hey, I’m having similar issues as well. I’m on the Halls of Origination scenario, and every time I reach the console room, by game starts sporadically freezing. It starts off manageable, but irritating. By the time the Sun-Priest miniboss spawns, my game becomes basically unplayable.
And not only does it freeze up my game - it freezes up my ENTIRE machine. I’ve had to manually shut down my MacBook four times before finally giving up on the scenario.
My game crashes my entire MacBook Pro if an enemy uses a AoE attack. Happens nonstop.
Ok everyone my fix was going to in game graphics settings, turning my window size all the way up to my computers resolution (5k for me) and then turning resolution scale down to around 50%.
Hope this helps someone…
so since this patch drop my Mac 2017 has not been running like it did in 8.2.5 like my game freezes HARD!!! I was running the junkyard and whatnot and I couldn’t even finish because I would be stuck and either be dead or just kicked from the group not to mention the fps drop and large ui for some reason I tried to reset the ui with no luck so any help would be awesome please and or thank you would love to go back to playing wow lol
2.3 GHz Dual-Core Intel Core i58 GB 2133 MHz DDR4iMac (21.5-inch, 2017)Intel Iris Plus Graphics 640 1536 MB
I have a 2017 MacBook Pro OS 10.15.2 and am having the same issues. Ever since 8.3 when I get near certain in game graphics like paladin consecration, I either freeze for 30 seconds or my computer crashes and restarts. This never ever happened before 8.3.
This doesn’t solve the memory leaking or whatever the main issue is, this just fixes the blurriness…I haven’t been able to play, progress, or gear up with my guild because of this and you guys don’t seem to give a crap at all.
Cool, now it’s clearer. Oh wait it still crashes and restarts the Mac.
This thread is intended for Fuzzy Graphics and FPS drops. If you are experiencing these issues, please refer to this post.
For the Mac Crashes, stuttering, or freezing issues, please refer to this thread to continue the discussion. These issues are completely different from the fuzzy graphics issue.
This works! Thank you so much. The fuzzy graphics was bothering me.
I have MacBook Pro 2018
macOS Catalina
I managed to fix the graphics due to helpful directions/ tips from this thread. However whenever I’m in the game/raids/dungeons, my Mac freezes up EVERY few seconds. So its honestly a gamble when I play. Several times it actually crashed and forcibly shut down my Mac. This NEVER happened (this extreme and frequently) in patch 8.2. I just hope this gets resolved soon because I am unable to progress in the game.
MacBook Pro 2018 Touch Bar
macOS Catalina