Hi, I am aware that this happens on other themes or in WordPress in general.
When I would like to preview the changes for tablet or mobile version, the default WordPress preview does not work. It allows me to open the preview window in a separate window at least. But, it is pointless to use this feature.
How do you guys preview the responsiveness when working on WordPress?
the device previews are still very experimental in WordPress – but we have integrated them into GenerateBlocks 1.2 so they at least it will re-render the page using the device specific CSS.
Simplest method for preview device responsiveness is using your Browser developers tools on the front end – Right click > Inspect and look for the mobile device icon ( in chrome ) in the menu bar. For CSS Layouts its really rather good.