Bug: custom indent doesn't always work

Using this: https://github.com/facebook/lexical/pull/3802
I am noticing that there are several occasions where the custom indent is not applied, and the default 20px appears. If I tab on that node, it automatically adjust to the corresponding indent.

Lexical version: 0.8.1

## Steps To Reproduce

1. Use my code-sandbox, where indent=40px and also I extend paragraphNode so that each inserted paragraph has the same indentation as the previous one.
2. Press enter on an indented paragraph. The new paragraph will have the same __indent but will be calculated over the default 20px.

Link to code example: https://codesandbox.io/s/angry-rosalind-969j13?file=/src/Editor.js

https://www.loom.com/share/998a64bb54d24b83bd50beb9ea9ee58d
I just realized that Loom didn't record devtools... but it's still understandable

## The current behavior
Custom Indent is not displayed

## The expected behavior
Custom Indent should be displayed