Markdown Preview Empty in v0.30.0 #2280

Describe the bug
I have just posted an issue found here about bookstack's frontpage. Before I posted the issue I wanted to see if this was because of a bug in my current version so I decided to upgrade to BookStack v0.30.0. After my upgrade the problem still persited so I went ahead and made an issue. I have now noticed a secondary issue that has arised only after I updated to BookStack v0.30.0.

What is happening is when I go to edit the page the markdown preview is completley empty. The conent only appears if I refresh the page in the editor. I have found this is inncosistent and I cannot decipher what is causing the issue/why the issue sometimes doesn't appear. (I'd say is happening with 3/4 of the time that I edit a page)

Steps To Reproduce
Steps to reproduce the behavior:

1. Update to BookStack v0.30.0
2. Click on edit
3. Preview is not loaded (sometimes)

Expected behavior
Content loads on preview page when editor is open

Screenshots
Before Refresh button (on browser) is hit:

After Refresh button (on browser) is hit:

Ignore my messy example code in screenshot, just needed some content to show

Your Configuration (please complete the following information):

• Exact BookStack Version (Found in settings): v0.30.0
• PHP Version: 7.3.22 (cli)
• Hosting Method (Nginx/Apache/Docker): Docker
• Editor: Markdown