Describe the current behavior
I recently noticed markdown formatting breaking in my recent notebooks.
Trailing spaces were trimmed which removed line breaks.
This happens when the notebook is saved and reopened.
I can also recreate the issue by copy and pasting a markdown cell with double space line breaks.
The new cell will have trailing spaces removed, removing the line breaks.

Describe the expected behavior
Pasted cells should be identical to the original.

What web browser you are using
Firefox and edge.

Additional context
https://colab.research.google.com/gist/bingbong-sempai/86adb536987d7d37c9ff606f5bdf0b8d/markdown-bug.ipynb
The spaces were lost when the notebook was copied to gist.