As described in this issue, using one of our One UI libraries (both sesl and the old Design lib) will cause issues with the Android Studio Layout Editor. This happens because Samsung's text styles use a custom fontFamily which is not available on AOSP. This repository contains a font pack to replace the AOSP one included in Android Studio.
Download the repo archive and extract it, navigate to the plugins/design-tools/resources/layoutlib/data directory inside your Android Studio folder and replace the "fonts" folder with the one provided in this repo.
Before applying the new font pack we suggest you to make a backup of your current "fonts" folder, since this may break some components such as the Android Studio Updater.