I tested this in Beta 126.96.36.1992 and Production 188.8.131.520
There seems to be a formatting issue when you move a SQL tab between sessions.
If I have a normal select like (forum has stripped out tab characters but each space is a tab)
when I use real tab characters for formatting then when I choose to move that statement between sessions (I use the drop down box with the sessions listed in it), say from latest-dev to prev-dev, it replaces all the tabs with spaces. Note this is not a saved file, just in a tab I want to use in a different session.
This becomes a bigger issue when you do something like extract DDL for a package in dev and then change the session to previous dev and then run the ddl script to recreate the package. All the tabs are gone. (which violates our standards of using real tabs)
You can get around this if you save the DDL to a file and then open and run the file in the other session but it involves the extra steps of saving and then opening the file which is less convenient.