[Modal] Blur doesn't work in modal without background

[staniel359]

Bug Report

Blur doesn't work in modal without background. The element is just transparent like its parent.

But somehow it works in transparent segment. (See Expected result).

Steps to reproduce

1. Create a modal with background: none
2. Inside <div class="content"> place a child element with backdrop-filter: blur(0.5rem)

Expected result

To have a blur.

Actual result

Testcase

See Steps to reproduce

Screenshot (if possible)

See above.

Version

2.9.3