When message "edit" is clicked the text shifts which causes need to readjust

It would be nice if the edit window wouldn't shift or reflow the text.

Problem story (Desktop):

1. I post a message (content less relevant, length relevant):
   
2. I click “Edit”: 
   
3. The text window shifts up and gets narrower which causes text to reflow:
   
4. Spend 1-30 seconds to find the text I wanted to edit again (especially with longer text and the sentences on the edges)

The overlap shows what happens to the text when you click "edit" on a message:

Or the GIF:

The Mobile experience is even worse, with a completely different window being opened and having a small scroll window to work with…