I am not sure if this is cause from Hearthstone (I believe it might be). After installing the latest patch on the latest version of macOS, 10.15.5, my OS seems to get sluggish. I was not able to get a screen shot, but Activity Monitor showed a large amount of CPU usage coming from Hearthstone - something that did not happen in previous patches.
I am not sure if this is going to happen again, but I thought I would let ya’ll know.
How have things been since now? Have you noticed any change in the game’s resolution? Often when we find this type of problem, the game is running at a very high resolution which is VERY CPU/GPU intense. This is quite common on retina monitors. If the problem persists, see if it stops in windowed mode.
Since posting, I have no longer had this symptom. Everything is running fine on my end.
Thanks for the follow up!
I was astonished by how much better the graphics got on my 2015 iMac with 5K Retina. The latest patch turned the game from stutter-y into absolutely beautiful.
Thank you, Blizzard!