Image Block's max-width is not 100% in the Editor, while following max-width 100% at the frontend

[frankyhung93]

Describe the bug
At the backend(Gutenberg Editor):

• I created an image block within the first column in a 2-col columns block. I set the image to display 100% under Image Dimensions then it becomes too large and overshoots the column's boundary.

At the frontend(after the page is saved):

• the Image follows the css max-width: 100% as defined in wp-includes/css/dist/block-library/style.css?ver=5.5.1 and fills up 100% of the column's width.

Screenshots
(In Editor) The image block in the first column:

(In Editor) The second column shown with the background of the oversized img from the first column:

Editor version (please complete the following information):

• WordPress version: 5.5.1
• Does the website has Gutenberg plugin installed, or is it using the block editor that comes by default? "default"

Desktop (please complete the following information):

• OS: macOS Catalina 10.15.6
• Browser: Chrome
• Version: 85.0.4183.102

[paaljoachim]

Hi @frankyhung93

I believe this is a duplicate of this issue (I am linking to a comment I just made in the other issue.)
#12168 (comment)

We can then close your issue. Thank you for bringing it up!
If I am mistaken let me know and I will reopen the issue.