[Blocksy] Switching responsive preview in Safari freezes browser and shoots up to 100% CPU usage

[andeng1106]

Describe the bug
Reported by Blocksy.

Responsive preview is unusable with Safari 15.4, freezes browser
Details: Create a page with multiple Stackable elements -- easy to import a Blocksy demo. Open the Gutenberg editor and use the Preview button to switch responsive views. Notice the browser shoots up to 100% CPU usage and the whole browser tab freezes, elements blank out, options cannot be clicked anymore -- basically the only way out is to close the tab. Same behaviour is present with the default 2021 theme, so not Blocksy’s fault. I will also add that the responsive preview feature works flawlessly in Chrome, regardless of the theme used.

To Reproduce
Steps to reproduce the behavior:

1. Create a page with multiple stackable elements or use a Blocksy starter site
2. Open the Gutenberg editor and use the Preview button to switch responsive views
3. Check if the CPU usage shoots up to 100% and the browser freezes
4. Also check if elements blank out and options can't be clicked anymore

Expected behavior

• CPU Usage should not shoot up to 100%.
• Responsive preview should be optimized

Screenshots

Screen.Recording.2022-04-26.at.11.22.01.mov

Desktop (please complete the following information):

• OS: MacOS
• Browser: Safari
• Browser Version: 15.4