Featured image sizes used to adjust according to the number of columns used with Stacks. Somewhere along the line this has changed. I noticed this by doing a website speed test.
All my featured images are 850×450 and with in my case 3 or 4 rows of posts, this used to be downsized automatically to 600×318 by using the medium size image itself automatically. Now the 850×450 is used no matter what.
It still works for mobile view. Then the 600×318 size image is used.
Any help would be appreciated 🙂
Website: Here