I am sure this has been posted before, but I didn't see it, so doesn't hurt to repost it for those that don't like to search to much...
My example is moving from the OLD Shadowlands to the NEW Shadowlands and using Windows 7, so you might need figure out what your HE#### number is by common sense and deduction by filenames. HE1034 is the old shadowlands number.
Chat boxes, friends list comments, and some UI changes and player settings are reset like you were created on a new server, these are the steps that I did and completely worked.
Click on the Windows Start and in the Run area type: %appdata%
This will open a explorer window, go to the address bar and backspace "roaming" and hit enter
Now select the "LOCAL" folder
Browser through the following folders: Local -> SWTOR -> swtor -> settings
Inside the settings folder you see a list of files, you want to delete any of the he1093 files that are created since you logged into the new one and then RENAME all the he1034 files to he1093.
ONLY CHANGE THE 34 to 93, nothing else.
Log in and you will have all your settings back.