I'm sorry to reopen this post but I've been honestly trying to solve this since last February.
The problem is noticed specially when opening in mobile.
The thing is... images in jact folder are huge! Some with 800x600 px with 100Kb come smaller with 300Kb; this means there is not optimization at all and is better using the 800x600 px optimized rather than a smaller picture not optimized. That shouldn't work like that.
For example the image in the following screenshot has dimensions of 600x450 px when it's shown on the screen as a 96x72 px image. That's six times the size that it needs to be and there's a lot more like that!
https://i.imgur.com/XL4lemR.png
I've optimized "manually" the pictures inside jact folder but this doesn't seem to be enough. So please tell me what am I doing wrong.?
For Focus template what should exactly be the Medium image width and height and Small image width and height?
Some help please?
Thanks in advance
Edit: as you can see in the picture I've sent, he is pulling medium image size when it should be pulling small image size (that another problem, beside the non optimization of the pictures in jact folders).